View source for Boo

{{about|the ghost enemies that appear throughout the [[Super Mario (franchise)|''Super Mario'' franchise]]|the [[microgame]] from [[WarioWare: D.I.Y. Showcase]]|[[Boo (microgame)]]|the area in Mario Party 10|[[Boo (area)]]}}
{{redirect|Boo Buddy|the circular group of Boos|[[Boo Buddies]]}}
{{distinguish|Bloo}}
{{species infobox
|collapsed=true
|image=[[File:MPS Boo Artwork.png|250px]]<br>Artwork from ''[[Mario Party Superstars]]''
|first_appearance=''[[Super Mario Bros. 3]]'' ([[List of games by date#1988|1988]])
|latest_appearance=''[[Mario & Luigi: Brothership]]'' ([[List of games by date#2024|2024]])
|latest_portrayal=[[Sanae Uchida]] ([[List of games by date#2004|2004]]–present)
|variants=[[Big & Little Boo]]<br>[[Big Boo]]<br>[[Blindfold Boo]]<br>[[Block Boo]]<br>[[Bomb Boo]]<br>[[Boo Balloon]]<br>[[Boo Buddies]]<br>[[Boo Buddy Snake]]<br>[[Boo Crew]]<br>[[Boo Guy]]<br>[[Boo Stack]]<br>[[Broozer]]<br>[[Dark Boo]]<br>[[Disappearing Boo Buddy]]<br>[[Eerie]]<br>[[Fishing Boo]]<br>[[Frame Boo]]<br>[[Ghost Goomba]]<br>[[Glohm Boo]]<br>[[Gold Boo]]<br>[[Hammer Knight]]<br>[[High Boo]]<br>[[Jelly Ghost]]<br>[[Mad Boo]]<br>[[Mini Boo]]<br>[[Paper Boo]]<br>[[Paper Macho Boo]]<br>[[Peepa]]<br>[[Red Boo]]<br>[[Stretch]]<br>[[Tail Boo]]
|comparable=[[Yarikuri Obake]]
|notable=[[Boo (Mario Party 4)|Boo (''Mario Party 4'')]]<br>[[Bootler]]<br>[[Captain Boo]]<br>[[The Creepy Steeple Boo]]<br>[[Franky]]<br>[[Herbert]]<br>[[Igor]]<br>[[King Boo]]<br>[[Lady Bow]]<br>[[Lahla]]<br>[[List of Boos in Luigi's Mansion|''Luigi's Mansion'' Boos]]<br>[[List of Boos in Luigi's Mansion: Dark Moon|''Luigi's Mansion: Dark Moon'' Boos]]<br>[[List of Boos in Luigi's Mansion 3|''Luigi's Mansion 3'' Boos]]<br>[[Peeka]]<br>[[Phantom (character)|Phantom]]<br>[[Stanley (Paper Mario)|Stanley]]
}}
{{quote|Mind turning around for a minute?|Boo|[[Paper Mario: Color Splash]]}}
'''Boos''', originally known as '''"Boo" Diddlys'''<ref>{{cite|date=1990|title=''Super Mario Bros. 3'' instruction booklet|publisher=Nintendo of America|language=en-us|page=38}}</ref> (a nod to the late American R&B singer {{wp|Bo Diddley}}) and later '''Boo Buddies'''<ref>{{cite|date=1991|title=''Super Mario World'' instruction booklet|publisher=Nintendo of America|language=en-us|page=24}}</ref><ref>{{cite|date=1991|title=''Yoshi'' (NES) instruction booklet|publisher=Nintendo of America|language=en-us|page=5 and 12}}</ref><ref>{{cite|date=1991|title=''Yoshi'' (Game Boy) instruction booklet|publisher=Nintendo of America|language=en-us|page=4 and 11}}</ref><ref>{{cite|author=Miller, Kent and Terry Munson|date=1995|title=''Super Mario World 2: Yoshi's Island'' Player's Guide|publisher=Nintendo of America|language=en-us|page=[[media:SMW2 Guide 126.jpg|126]]}}</ref><ref>{{cite|date=January 1998|title=''[[Nintendo Power]]'' Volume 104|author=Tilden, Gail, et al.|page=16|quote=Still haunting the Yoshis, the Boo Buddies bust back onto the scene.|publisher=Nintendo of America|language=en-us}}</ref><ref>{{cite|author=Hodgson, David S J|date=October 21, 2003|title=''Super Mario Advance 4: Super Mario Bros. 3'' Prima's Official Strategy Guide|publisher=[[Prima Games]]|language=en-us|isbn=0-7615-4425-9|page=19, 35, 45, 56, 57, 66, 71, 82, 85, 97, 102, 103, 104, 121, 122, 125, and 126}}</ref> or simply '''Ghosts''',<ref>{{cite|quote=The candle in this contraption scares Ghosts into covering their eyes, so you can safely walk your Mini right through them.|url=play.nintendo.com/news-tips/tips-tricks/mini-mario-friends-amiibo-challenge-items|title=Mini Mario & Friends: amiibo Challenge Items|publisher=Play Nintendo|language=en-us|accessdate=March 31, 2020|archive=web.archive.org/web/20200816215214/https://play.nintendo.com/news-tips/tips-tricks/mini-mario-friends-amiibo-challenge-items}}</ref> are recurring ghost enemies that first appear in ''[[Super Mario Bros. 3]]''. They are a type of white spherical ghost with menacing and normally open mouths. They are known for their large tongues and small stubby arms. However, the most distinctive characteristic of the Boos is their shy personality, as they cover their faces when someone looks directly at them, but then uncover and move after the character when their back is turned; this exact behavior is used by {{iw|wikirby|Mumbies}} in the ''{{iw|wikirby|Kirby (series)|Kirby}}'' series.

[[Shigeru Miyamoto]] got the idea for Boo from the wife of his coworker and close friend [[Takashi Tezuka]], as she is shy but one day got very angry with him for coming home late from work.<ref>{{cite|author=Stuart, Keith|date=September 13, 2010 - 08:56 EDT|url=www.theguardian.com/technology/gamesblog/2010/sep/13/games-gameculture|title=Super Mario Bros: 25 Mario facts for the 25th anniversary|publisher=The Guardian|language=en|accessdate=May 24, 2024}}</ref><ref>{{cite|author=Tilden, Gail, et al.|date=January 1996|url=archive.org/stream/Nintendo_Power_Issue001-Issue127/Nintendo%20Power%20Issue%20080%20January%201996#page/n26/mode/1up|page=25|title=''Nintendo Power'' Volume 80|publisher=Nintendo of America|language=en-us}}</ref>
==History==
===''Super Mario'' series===
====''Super Mario Bros. 3'' / ''Super Mario Advance 4: Super Mario Bros. 3''====
[[File:SMB3Boo.jpg|thumb|left|Artwork of a "Boo" Diddly from ''Super Mario Bros. 3'', its debut appearance]]
"Boo" Diddlys<ref>{{cite|date=1990|title=''Super Mario Bros. 3'' instruction booklet|publisher=Nintendo of America|language=en-us|page=38}}</ref> appear in ''Super Mario Bros. 3''. They are first encountered in {{world link|2|fort|World 2-Fortress}}, and are largely found in fortress stages, though are not exclusive to them. A "Boo" Diddly shields its face if looked at, but chases the player character if not looked at. "Boo" Diddlys can be defeated only from either the effects of a [[Hammer Suit]] or a [[Super Star|Starman]], or from a [[Koopa Shell|Koopa shell]]. "Boo" Diddlys are depicted with either a dark-blue or dark-red outline in the [[Family Computer]] and [[Nintendo Entertainment System]] version, depending on the level.

"Boo" Diddlys have a variant called [[Stretch]]es, which are fixed to certain white platforms and lack their characteristic shyness.

====''Super Mario World'' / ''Super Mario World: Super Mario Advance 2''====
[[File:SMWBoo.png|frame]]
"Boo" Buddies (called "Boo" Diddlys earlier in development)<ref>{{cite|author=TCRF|title=[[tcrf:Development:Super Mario World (SNES)/Background Graphics and Tilemaps/Credits#Enemy Cast List|Development:Super Mario World (SNES)/Background Graphics and Tilemaps/Credits § Enemy Cast List]]|publisher=The Cutting Room Floor|language=en|accessdate=August 6, 2020}}</ref> appear in ''[[Super Mario World]]'' and [[Super Mario World: Super Mario Advance 2|its reissue]]. They are solely encountered in the [[Ghost House]] levels. "Boo" Buddies behave identically but move slower than before, a consistency retained throughout the [[Super Mario (series)|''Super Mario'' series]]. "Boo" Buddies appear to have multiple tails. "Boo" Buddies change their face very briefly if looked at for long enough, and groups of them make a variety of facial expressions. More varieties are introduced in the game, including [[Block Boo|Boo Buddy Block]]s, [[Boo Buddy Snake]]s, [[Boo Crew]]s, [[Boo Buddies|Circling Boo Buddies]], [[Eerie]]s, [[Disappearing Boo Buddy|Disappearing Boo Buddies]], and the [[Big Boo]], though Stretches are absent. A "Boo" Buddy is defeated only from the effects of [[Super Star]]s or being hit by a [[Grab Block]].

====''Super Mario Land 2: 6 Golden Coins''====
Boo Buddies appear in the [[Pumpkin Zone]] levels of ''[[Super Mario Land 2: 6 Golden Coins]]'', in addition to their introduced [[Ghost Goomba]] variants. Boo Buddies move in a slower, wave-like pattern than before. They can be defeated by a [[Koopa Shell]].

====''Super Mario 64'' / ''Super Mario 64 DS''====
{{quote|Ghosts...don't...DIE! Heh, heh, heh! Can you get out of here...alive?|Message from Big Boo's Haunt}}
[[File:Boo 64.png|thumb|120px|left|In-game model from ''Super Mario 64'']]
[[File:SM64DS BigBoo.png|thumb|175px|In-game model from ''Super Mario 64 DS'']]
Boos (also called '''Baby Boos''')<ref>{{cite|author=Prima Bath|date=April 7, 1999|title=''Nintendo 64 Game Secrets, 1999 Edition'' Prima's Official Strategy Guide|publisher=Prima Games|isbn=0-7615-2103-8|page=84-87}}</ref> appear in ''[[Super Mario 64]]'' and ''[[Super Mario 64 DS]]''. They use their design from ''[[Mario Party 4]]'' in the latter version. Boos are encountered in the [[Courtyard (Peach's Castle)|courtyard]] of [[Peach's Castle]] and in [[Big Boo's Haunt]]. Big Boos are recurring mini-bosses in the latter location, as well as a different [[King Boo|Big Boo]] in the [[Big Boo Battle]] stage in the remake only. When Boos are looked at, they become partially visible, but are fully opaque otherwise and follow the player character. Boos take away two units of [[Health Meter|health]] on contact. The Boos in the courtyard hold a [[coin|Yellow Coin]] each, and those in Big Boo's Haunt each have a [[Blue Coin]]; the remake changes the former instance to [[Red Coin]]s until the player collects all eight and then the [[Power Star]]. Boos are defeated from either a [[punch]], a [[kick]], a [[Ground Pound|Pound the Ground]] attack, or [[Luigi]]'s [[Spin Jump|spin jump]] in the remake only. Boos cannot be defeated by [[Yoshi]] in the remake, and it is spit out if Yoshi attempts to do so.<ref>{{cite|quote=You...can't...EAT...ghosts! Eee hee hee!|author=Boo|date=2004|title=''Super Mario 64 DS''|publisher=Nintendo|language=en}}</ref> A line of dialogue displays each time a Boo is defeated in the [[Go on a Ghost Hunt|first mission]] of Big Boo's Haunt.<ref>{{cite|quote=Ghosts...don't...DIE! Heh, heh, heh! Can you get out of here...alive?|author=Boo|date=1996|title=''Super Mario 64''|location=Big Boo's Haunt|publisher=Nintendo|language=en}}</ref> A Big Boo appears in the hallway of the Mushroom Castle after twelve Stars are collected, or 15 in the remake, while the remake additionally features a normal Boo in the same position after eight Stars are collected, disappearing if the eight [[Red Coin]]s in the courtyard are collected and being replaced with the Big Boo either way once 15 are collected. In several missions of the remake, a Boo wearing a [[Luigi Cap|Luigi's cap]] appears in the stage.

====''Super Mario Bros. Deluxe''====
{{multiframe|[[File:Super Mario Bros Deluxe Boo.png]] [[File:SMBDX Green Boo.png]] [[File:SMBD Redboo.png]] [[File:BlackBoo.png]]|The Boos from<br>''Super Mario Bros. Deluxe'',<br>arranged by speed}}
Boos appear in ''[[Super Mario Bros. Deluxe]]''. They are competitors in the "You VS. Boo" mode, competing to reach the [[Goal Pole|flagpole]] before the player can. Boos do not damage the player character on contact. If the Boo is defeated within a time frame, it flies away, being replaced by a faster green Boo, then by a faster red Boo, and lastly a '''Black Boo'''<ref>{{cite|date=1999|title=''Super Mario Bros. Deluxe'' instruction booklet|publisher=Nintendo of America|language=en-us|page=20}}</ref> with a yellow outline. The Black Boo travels in a way mimicking the player's best time.

====''Super Mario Sunshine''====
[[File:SMS Boo Artwork.jpg|thumb|left|100px|A Boo from ''[[Super Mario Sunshine]]'']]
Boos return in ''[[Super Mario Sunshine]]''. They have a different design consisting of drooping eyelids, blue circles around their black pupils, and long, coiled tails, due to being made of [[goop]].<ref>{{cite|author=Sakai, Kazuya (Ambit), et al.|date=October 19, 2015|title=『スーパーマリオブラザーズ百科: 任天堂公式ガイドブック』 (''Super Mario Bros. Hyakka: Nintendo Kōshiki Guidebook'')|publisher=[[Shogakukan]]|language=ja|location=Tokyo|isbn=978-4-09-106569-8|page=107}}</ref> They are encountered in [[Sirena Beach]] only, inside of [[Hotel Delfino]]. Two varieties of Boo appear, [[Block Boo|Pink Boo]]s and [[Sleepy Boo]]s, and the boss fought below Hotel Delfino is [[Big Boo (character)|King Boo]]. Boos move around in slow, swooping motions. They do not react if looked at. There are Boos that are mostly invisible, besides a distorted visual effect, but spraying them with water makes them become increasingly visible. The invisible Boos take on disguises such as Yellow Coins or Blue Coins, differentiated only from not spinning at a constant pace, or [[Shadow Mario]], differentiated by appearing lighter colored, lacking the [[magic brush]], and the Shadow Mario theme not playing. If a disguised Boo is approached, it laughs and bumps into Mario, unless it has been sprayed prior.

====''New Super Mario Bros.''====
[[File:NSMBDS Boo Sprite.gif|frame|right]]
Boos appear in ''[[New Super Mario Bros.]]'' They are encountered in Ghost Houses and [[World 8-1 (New Super Mario Bros.)|World 8-1]]. They act the same as in ''Super Mario Bros. 3'', though the ways of defeating them include a [[Koopa Shell|Shell]], a [[Super Star|Starman]], a [[Mega Mushroom]], or a [[Blue Shell]]. The game introduces [[Balloon Boo]]s, which inhale air to inflate themselves, and [[Broozer]]s, which are boxers.

====''Super Mario Galaxy''====
[[File:Mario Seek.png|thumb|Screenshot from ''Super Mario Galaxy'' showing Mario look at a Boo]]
Boos appear in ''[[Super Mario Galaxy]]''. Normally, Boos become transparent when the player character looks at them but are opaque and go after the player character if they are not looking. There is also an underwater type that simple floats back-and-forth a short distance oblivious to the player character. A Boo can be defeated mainly from any ray of light or when touched by [[Rainbow Mario]]. Boos can be spun off course from a spin attack. Varieties that appear include [[Big Boo|Atomic Boo]] and the debuting [[Bomb Boo]]s, and there is an Atomic Boo character who is raced, the [[Spooky Speedster]]. One of the power-ups, [[Boo Mario]], has the player character become a Boo, retaining only his face and cap. Boos are attracted to Boo Mario and follow him. If a Boo hits Boo Mario, he does not take damage but does lose the power-up.

[[Captain Toad]] also indirectly suggests that Boos eat people, as he worried that Luigi might have been eaten by ghosts.
=====Appearances=====
<div class="contentbox mw-collapsible mw-collapsed"data-expandtext="Show appearances"data-collapsetext="Hide appearances">
*[[File:SMG Asset Sprite Star Cursor.png]] marks missions where they are completely absent.
*[[File:Galaxy StarP.png]] marks missions where they are loaded and may be visible, but cannot be encountered directly.
{|class="wikitable"style="text-align:center"
|-style="color:white;background:red"
!colspan=8|'''Normal'''
|-style="color:white;background:red"
!Domes
!Galaxies
!colspan=6|Missions
|-
|[[Kitchen (Super Mario Galaxy)|Kitchen]]
|[[Ghostly Galaxy]]
|[[File:Smg icon powerstar.png|link=Luigi and the Haunted Mansion]]||[[File:Galaxy StarP.png|link=A Very Spooky Sprint]]||[[File:Galaxy StarP.png|link=Beware of Bouldergeist]]||[[File:Galaxy StarP.png|link=Bouldergeist's Daredevil Run]]||[[File:Galaxy StarP.png|link=Purple Coins in the Bone Pen]]||[[File:Smg icon powerstar.png|link=Matter Splatter Mansion]]
|-
|[[Engine Room]]
|[[Sand Spiral Galaxy]]
|[[File:Smg icon powerstar.png|link=Choosing a Favorite Snack]]
|-
|[[Garden (Super Mario Galaxy)|Garden]]
|[[Deep Dark Galaxy]]
|[[File:Smg icon powerstar.png|link=The Underground Ghost Ship]]||[[File:SMG Asset Sprite Star Cursor.png|link=Bubble Blastoff]]||[[File:SMG Asset Sprite Star Cursor.png|link=Guppy and the Underground Lake]]||[[File:Smg icon daredevilcomet.png|link=Ghost Ship Daredevil Run]]||[[File:Smg icon purplecomet.png|link=Plunder the Purple Coins]]||[[File:Galaxy StarP.png|link=Boo in a Box]]
|-
|-style="color:white;background:red"
!colspan=8|'''Underwater'''
|-style="color:white;background:red"
!Domes
!Galaxies
!colspan=6|Missions
|-
|[[Bedroom (Super Mario Galaxy)|Bedroom]]
|[[Bigmouth Galaxy]]
|[[File:Smg icon powerstar.png|link=Bigmouth's Gold Bait]]
|}
</div>

====''New Super Mario Bros. Wii''====
Boos return in ''[[New Super Mario Bros. Wii]]''. They are depicted with a blue glow. Boos are encountered in Ghost Houses only. They behave identically as in ''New Super Mario Bros.'' Varieties that appear include [[Big Boo]]s, [[Broozer]]s, and [[Boo Buddies|Circling Boo Buddies]]. Every Ghost House on the world map has a Boo who watches the player character and laughs whenever he either enters or is kicked out from losing a life. Once the level is cleared, the Boo only covers its face henceforth. Boos are defeated only from the effects of a [[Super Star|Star]].

====''Super Mario Galaxy 2''====
Boos appear in ''[[Super Mario Galaxy 2]]''. They behave identically to their appearance in ''Super Mario Galaxy'', with both the normal and underwater types reappearing. Besides Bomb Boos returning, two variants make their debut: [[Octoboo]]s, a cross between an [[Octoomba]] and Boo, and [[Mega Boo]]s, larger than even Big Boos.
=====Appearances=====
<div class="contentbox mw-collapsible mw-collapsed"data-expandtext="Show appearances"data-collapsetext="Hide appearances">
*[[File:SMG Asset Sprite Star Cursor.png]] marks missions where they are completely absent.
*[[File:Galaxy StarP.png]] marks missions where they are loaded and may be visible, but cannot be encountered directly.
{|class="wikitable"style="text-align:center"
|-style="color:white;background:red"
!colspan=5|'''Normal'''
|-style="color:white;background:red"
!Worlds
!Galaxies
!colspan=3|Missions
|-
|[[World 3 (Super Mario Galaxy 2)|World 3]]
|[[Haunty Halls Galaxy]]
|[[File:SMG Asset Sprite Star Cursor.png|link=A Glimmer of Bulb Berry]]||[[File:Smg2 icon powerstar.png|link=Sneaking Down the Creepy Corridor]]||[[File:Smg2 icon prankstercomet.png|link=Spooky Cosmic Clone Chase]]
|-
|[[World 5 (Super Mario Galaxy 2)|World 5]]
|[[Boo Moon Galaxy]]
|[[File:Smg2 icon powerstar.png|link=Silver Stars Pop-Up]]||[[File:Smg2 icon powerstar.png|link=Haunting the Howling Tower]]||[[File:Smg2 icon powerstar.png|link=The Star in the Sinking Swamp]]
|-
|-style="color:white;background:red"
!colspan=5|'''Underwater'''
|-style="color:white;background:red"
!Worlds
!Galaxies
!colspan=3|Missions
|-
|rowspan=2|[[World 6 (Super Mario Galaxy 2)|World 6]]
|[[Slimy Spring Galaxy]]
|[[File:Smg2 icon powerstar.png|link=The Deep Shell Well]]||[[File:Smg2 icon powerstar.png|link=The Chimp's Coin Challenge]]
|-
|[[Battle Belt Galaxy]]
|[[File:Smg2 icon powerstar.png|link=Mini-Planet Mega-Run]]||[[File:Smg2 icon prankstercomet.png|link=Mini-Planet Daredevil Run]]||[[File:Smg2 icon powerstar.png|link=Snacktime for Gobblegut]]
|}
</div>

====''Super Mario 3D Land''====
Boos appear in ''[[Super Mario 3D Land]]''. They behave similarly as before, but disappear briefly if hit by a tail whip from [[Tanooki Mario]] or one of [[Fire Mario]]'s [[fireball]]s. Their laugh is similar as in ''Super Mario 64''. Aside from Big Boos returning, two more variants are introduced: [[Tail Boo]]s, which have a tanooki tail, and [[Peepa]]s, which move in a set pattern.

====''New Super Mario Bros. 2''====
Boos return in ''[[New Super Mario Bros. 2]]''. They are encountered in Ghost Houses. There are Boos in {{world|4|ghosthousen2}} that push the wall either left or right, and they are not shy of being looked at. Boos otherwise are the same as in ''New Super Mario Bros. Wii'', except they can be defeated from the effects of either a Star or [[Gold Flower]]. Aside from Peepas returning, the game introduces the giant [[Boohemoth]]s and [[Gold Boo]]s, which Boos transform into while a [[Gold Ring]] during the effects of a Gold Ring. 

====''New Super Mario Bros. U'' / ''New Super Mario Bros. U Deluxe''====
[[File:BooNSMBU.png|thumb|Artwork from ''New Super Mario Bros. U'']]
Boos appear in ''[[New Super Mario Bros. U]]'' and [[New Super Mario Bros. U Deluxe|its port]]. They are the same as before, though [[Baby Yoshi]]s can defeat Boos. [[Big Boo]]s and [[Boo Buddies|Circling Boo Buddies]] both also return. Boos appear in an [[Enemy Course]] in the [[Soda Jungle#Haunted Area|haunted area]] of [[Soda Jungle]], where a [[Flying ? Block]] with the Super Star is required to defeat them.

====''Super Mario 3D World'' / ''Super Mario 3D World + Bowser's Fury''====
Boos appear in ''[[Super Mario 3D World]]'' and [[Super Mario 3D World + Bowser's Fury|its port]]. Their only differences are cosmetic, being more transparent, having a blueish glow like in ''New Super Mario Bros. Wii'' and its sequels unless stared at, in which case they have a reddish glow while emitting steam. Big Boos and Peepas also return.

====''Super Mario Maker'' subseries ====
{{multiple image
|align=left
|direction=horizontal
|footer=''Super Mario Bros.'' styled Boos from ''Super Mario Maker''
|image1=SMM-SMB-Boo.png
|width1=60
|image2=SMM-SMB-Boo-Hiding.png
|width2=60
|image3=SMM-SMB-Boo-Wings.png
|width3=53
}}
Boos are course elements in ''[[Super Mario Maker]]'', [[Super Mario Maker for Nintendo 3DS|its port]], and ''[[Super Mario Maker 2]]''. They have newly designed sprites for the ''[[Super Mario Bros.]]'' style, but are otherwise the same as in other entries of the ''Super Mario'' series. Boos can be inserted into [[Bill Blaster]]s, [[Block]]s, a [[Koopa Clown Car]], [[track]]s, or [[Warp Pipe]]s. Boos can be shaken to become [[Boo Buddies]] or dragged on to platforms to become [[Stretch]]es. Applying a [[Super Mushroom]] to a Boo changes it into a Big Boo, while giving it wings gives it faster movement. Boos in Koopa Clown Cars affect the vehicle to stop and close its eyes when looked at and sneak up on the player while they are not looking. In ''Super Mario Maker 2'', Peepas also appear in the ''Super Mario 3D World'' style, replacing Boo Buddies.

====''Super Mario Run''====
[[File:SMRBoo.png|frame|right]]
Boos appear in ''[[Super Mario Run]]''. They are encountered in Ghost House levels. Boos cover their eyes and float up and down while looked at, including if they are close to the player's vertical position, and turn to look at the player character. Boos otherwise follow in a quick, wavy motion. Boos are defeated by either jumping backward over them using a [[Backflip Block]] or a [[Wall Jump]]. The pink [[P Switch]] of certain levels defeat every Boo on-screen. Boos drop [[Key]]s, [[Coin]]s, or [[Color coin]]s upon defeat, with the item being slightly visible before their defeat. Boos in the level [[Dark and Stormy]] are defeated whenever lightning strikes happen. Boo cannot leveled. Besides Boos, Stretches also return.

There is a [[List of Kingdom Builder items in Super Mario Run|Boo Statue]] in Kingdom Builder, which has an interaction where it briefly covers its eyes. 
{{br|left}}

====''Super Mario Bros. Wonder''====
[[File:SMBWKingBoo.png|thumb|King Boo with several other Boos in ''Super Mario Bros. Wonder'']]
Boos are enemies in ''[[Super Mario Bros. Wonder]]''. They are designed similarly to their older artworks but still stick their tongues out. Boos behave identically as before, and are defeated upon contact with rays of light, like in ''Super Mario Galaxy''. Besides Boos, [[King Boo]] appears during one of the [[Wonder Effect]]s.
{{br}}

===DIC cartoons===
====''The Adventures of Super Mario Bros. 3''====
[[File:CartoonBoo.jpg|thumb|A "Boo" Diddly in ''The Adventures of Super Mario Bros. 3'' episode "[[Reign Storm]]".]]
Boos appear infrequently in ''[[The Adventures of Super Mario Bros. 3]]''. They are depicted with red eyes and yellow teeth. "Boo Diddlys" in the episode "[[Reign Storm]]" assist King Koopa by terrorizing the Mushroom Shopping Mall. 

Two Boo Diddlys appear in "[[Misadventures in Babysitting]]", where they are found in the dungeon sneaking behind and spooking [[Junior (The Adventures of Super Mario Bros. 3)|Junior]]. The same Boos are scared off by Luigi who makes a scary face at them. They are seen once more fleeing from lava caused by [[Ludwig|Kooky]]. In the episode, the Boos have deep, menacing laughs but high-pitched screams.

====''Super Mario World'' television series====
[[File:SMWTV Yoshi and Boo.jpg|thumb|left|Yoshi encountering a ghost in the ''Super Mario World'' television series episode "[[The Night Before Cave Christmas]]".]]
Ghosts, as they are called, appear in the episodes "[[Ghosts 'R' Us]]," "[[The Night Before Cave Christmas]]," and "[[The Yoshi Shuffle]]" of ''[[Super Mario World (television series)|Super Mario World]]''. They are designed much differently than in the previous show, being depicted similarly to their in-game sprite. "Ghosts 'R' Us" features a group of ghosts and a Big Boo chasing [[Yoshi]] through [[Wizenheimer]]'s haunted house. "The Night Before Cave Christmas" includes ghosts that scare Yoshi away. "The Yoshi Shuffle" includes ghosts in the audience at the start of the episode.
{{br}}

===''Nintendo Adventure Books''===
[[File:Capers.jpg|thumb|Boos chasing Luigi on the front cover of ''[[Koopa Capers]]'', the fourth of the ''Nintendo Adventure Books'']]
In ''[[Koopa Capers]]'', a Boo confronts Luigi if he decides to simply look through a keyhole in a fortress door, instead of barging through it. If Luigi decides to run away from it immediately, he will successfully escape, but if he decides to stand his ground, the Boo will chase him onto some floating blocks after he dodges its attack. Making a beeline for the door after mounting the blocks will allow the Boo to catch Luigi, but doing evasive techniques will allow him to escape it. When he begins his descent into the Magma Pit, Luigi will hear a Boo behind him, which causes him to pick up the pace, and escape it.

Illustrations of a Boo are used in puzzles in ''[[Dinosaur Dilemma]]'' and ''[[Flown the Koopa]]'', though none appear in the actual stories.

===''Super Mario World: Mario to Yoshi no Bōken Land''===
[[File:SMWM&YALBoos.png|thumb|left|Boos swarming Luigi, Yoshi, and Mario from ''Super Mario World: Mario to Yoshi no Bōken Land'']]
In the interactive OVA ''[[Super Mario World: Mario to Yoshi no Bōken Land]]'', Boos appear in a [[Ghost House]] that [[Mario]], [[Luigi]], and [[Yoshi]] are passing through. A Boo starts following Luigi, who is in the back, but every time he turns around, it disappears. Finally, he quickly does a double take, and turns just in time to see it re-materialize. He panics and Boos start swarming the group. Mario grabs a candle and lights it, which repels the Boos, and one drops a key they need to progress.
{{br}}

===''Yoshi''===
Boo Buddies are one of six types of falling objects in ''[[Yoshi (game)|Yoshi]]''. They are based on their appearance in ''[[Super Mario World]]''.

===''Mario Kart'' series===
====''Super Mario Kart''====
{{multiframe
|[[File:SMK Boo Item Box Sprite 1.png]]<br>[[File:SMK Boo Item Box Sprite 2.png]]
}}
'''Ghosts'''<ref>{{cite|date=1992|title=''Super Mario Kart'' instruction booklet|publisher=Nintendo of America|language=en|page=14}}</ref> are items in "2 Player" mode and background elements of [[SNES Ghost Valley 1|Ghost Valley 1]] [[SNES Ghost Valley 2|Ghost Valley 2]], and [[Ghost Valley 3]] in ''[[Super Mario Kart]]''. Using a Ghost item makes the user become transparent temporarily as the Ghost steals any item available from an opponent. Ghosts in the background laugh as the player character drives by.

====''Mario Kart 64''====
[[File:BooMK64.png|frame|left]]
Boos (named '''Ghost Bonuses''' on one occasion)<ref>{{cite|date=April 1997|title=''Nintendo Magazine System'' (AU) Issue 49|publisher=Catalyst Publishing|language=en-au|page={{file link|NMS Australia 49 MK64 drivers and items.jpg|39}}}}</ref> are items as well as background elements of [[N64 Banshee Boardwalk|Banshee Boardwalk]] and [[N64 Rainbow Road|Rainbow Road]] in ''[[Mario Kart 64]]''. Boos can be obtained by racers in one of the top two positions. When used, a Boo makes the user both invisible and invincible temporarily as it selects an opponent to steal an item from, unless the racers have no items. A player character affected by a Boo can pass any items, course obstacles, and racers by going through them. The CPUs also use Boos, but they do not steal items.

====''Mario Kart: Super Circuit''====
[[File:MKSC Boo Alternate Artwork.jpg|thumb|Artwork from ''Mario Kart: Super Circuit'']]
Boos, also named "ghosts",<ref>{{cite|author=Walsh, Doug|date=August 21, 2001|title=''Mario Kart: Super Circuit'' Official Racing Guide|publisher=BradyGames|language=en-us|isbn=0-7440-0091-2|page=92}}</ref> are items, background characters in [[GBA Boo Lake|Boo Lake]], and obstacles in [[Broken Pier]] in ''[[Mario Kart: Super Circuit]]''. When used as an item, the Boo makes the user invisible for about five seconds and slows down the leading racer. A CPU can now use a Boo to potentially steal the player's item and coins. The transparency effect lasts for five seconds. The Boos in Boo Lake hold candles to guide player characters, while the Boos on Broken Pier take the coins

====''Mario Kart: Double Dash!!''====
Boos make a cameo in ''[[Mario Kart: Double Dash!!]]''. They are visible in portraits within the battle course [[GCN Luigi's Mansion|Luigi's Mansion]]. [[King Boo]] has a much larger role, being a playable character.
{{br|left}}

====''Mario Kart Arcade GP'' subseries====
[[File:MKAGPDX Boo.png|thumb|120px|left|Boo item from ''Mario Kart Arcade GP DX'']]
Boos are items in ''[[Mario Kart Arcade GP]]'', ''[[Mario Kart Arcade GP 2]]'', and ''[[Mario Kart Arcade GP DX]]''. A Boo slows whomever it hits temporarily. The item has a variation titled '''Triple Boo'''.
{{br|left}}
====''Mario Kart DS''====
Boos, named '''Boo Hoo''' in British English,<ref>{{cite|date=2005|title=''Mario Kart DS'' European English instruction manual|url=cdn02.nintendo-europe.com/media/downloads/games_8/emanuals/nintendo_ds_21/Manual_NintendoDS_MarioKartDS_EN.pdf|format=PDF|publisher=Nintendo|language=en-gb|page=12}}</ref> are items, background characters in {{classic link|N64|Banshee Boardwalk}}, and cameo in portraits in [[DS Luigi's Mansion|Luigi's Mansion]] in ''[[Mario Kart DS]]''. When used, a Boo makes the user partly invisible while stealing an item from the nearest racer. Using a Boo item does not slow the user while on offroad surfaces. Boos are obtainable by racers between 3rd to 7th place. The Boos in {{classic link|N64|Banshee Boardwalk}} only let out a laugh as a player character drives by.

====''Mario Kart Wii''====
Boos are background characters in the course {{classic link|SNES|Ghost Valley 2}} and cameo in [[Bowser's Castle (Mario Kart Wii)|Bowser's Castle]] in ''[[Mario Kart Wii]]''. In the former, they only laugh as racers drive by before disappearing eventually, while in the latter, artwork of Boo and [[Dry Bones]] from ''[[Mario Party 7]]'' is shown. King Boo has a much larger role again as a playable character.

====''Mario Kart 7''====
Boos are background characters of the course {{classic link|DS|Luigi's Mansion}} and spectators on [[3DS Toad Circuit|Toad Circuit]] and {{classic link|N64|Luigi Raceway}} in ''[[Mario Kart 7]]''. The Boo portraits in {{classic|DS|Luigi's Mansion}} replace every portrait ghost portrait, and they push against their paintings as player characters drive nearby.

====''Mario Kart 8'' / ''Mario Kart 8 Deluxe''====
[[File:Hammer Knight MK8D.jpg|thumb|A Boo inside a Hammer Knight from ''Mario Kart 8'']]
[[File:MK8D Luigi and Boo Item Screenshot.png|thumb|left|Luigi holding a Boo from ''Mario Kart 8 Deluxe'']]
Boos are obstacles in the course [[Twisted Mansion]] in ''[[Mario Kart 8]]'' and ''[[Mario Kart 8 Deluxe]]'' as well as items in the latter. The Boos near the gliding section of Twisted Mansion can be landed on, and the course also has [[Hammer Knight]]s towards the end. Boos also float around in {{classic link|GCN|Luigi's Mansion}} in ''Mario Kart 8 Deluxe'' and {{classic link|GBA|Boo Lake}} in the ''[[Mario Kart 8 Deluxe – Booster Course Pass]]'', replacing candle Boos from the original iteration in the latter course.

As items, Boos steal an item from a random opponent in front of the user, even if they are under invincibility effects. They can no longer be used to take off-road shortcuts. If there is no item to steal, the Boo gives the user a Mushroom. Only one Boo can be used on a course at once, excluding if an opponent is still under invisibility effects. A Boo can steal any timed or multiple usage item, except for a [[Crazy Eight]], [[Piranha Plant]], or [[Bullet Bill]], and the duration or usage is not carried over to the player character.<ref>{{cite|author=Mankalor|date=May 8, 2017|url=youtu.be/OUdaqb7Cj2I|title=Mario Kart 8 Deluxe Tips - Boo Item Analysis|publisher=YouTube|accessdate=May 9, 2017}}</ref>
{{br}}

====''Mario Kart Tour''====
[[File:MKT Boo Wooden Cutout.png|thumb|A wooden cutout of two Boos in ''Mario Kart Tour'']]
Boos are non-playable characters in ''[[Mario Kart Tour]]''. They are encountered in [[SNES Ghost Valley 1]], [[SNES Ghost Valley 2]], [[GBA Boo Lake]], [[DS Luigi's Mansion]], and [[RMX Ghost Valley 1]], behaving identically as before. [[Wooden cutout]]s of Boos also appear in the Ghost Valley courses and DS Luigi's Mansion. In every [[Halloween Tour]] since 2020, the [[Autumn Tour (2021)|2021 Autumn Tour]] and the [[Battle Tour]], [[Jack-o'-lantern]]s are scattered throughout the courses, some of which had Boo faces. King Boo returns as a playable character. A glider known as the [[Boo Masks]], based on Boos, is the signature glider of [[Princess Peach|Peach (Yukata)]].

====''Mario Kart Live: Home Circuit''====
Boos are obstacles in the course [[Boo Fortress]] in ''[[Mario Kart Live: Home Circuit]]''. They frighten any player who hits them.
{{br}}
===''Yoshi's Cookie''===
Boos are opponents in ''[[Yoshi's Cookie]]''. They are one of the opponents ranked on the easy difficulty. [[Eerie]]s and [[Fishing Boo|Fishin' Boo]]s both return.

===''Super Mario Adventures''===
Boos are antagonists in ''[[Super Mario Adventures]]''. A horde of them attack Mario and Luigi after the two are tricked into entering a haunted house. The Boos and a Big Boo trap the Mario Bros. but are held at bay from being stared at. The Boos continue going after a nearly exhausted Mario as he drags Luigi. The Boos and Big Boo find Mario [[Dr. Mario|dressed as a psychiatrist]] with Luigi as his nurse after barging in. The Boos and the Big Boo are reformed by Mario and Luigi after some discussion, and it is revealed that the Boos were mean since they were bullied. The Boos and Big Boo lastly lead Mario, Luigi, and Yoshi out of the haunted house, waving goodbye to them. Boos are also present during [[Princess Peach|Toadstool]]'s wedding.
{{br}}

===''Super Mario Bros.'' film===
While Boos do not physically appear in the 1993 [[Super Mario Bros. (film)|''Super Mario Bros.'' film]], a [[:File:VoteKoopaFilm.png|sign saying "NOW PLAYING BOO DIDLEY"]]{{sic}} can be seen in [[Dinohattan]].

===''Yoshi's Safari''===
[[File:YoshiSafariBoo65.png|thumb|left|A Big Boo from ''Yoshi's Safari'']]
Boos<ref>{{cite|date=1993|title=''Yoshi no Road Hunting'' instruction booklet|publisher=Nintendo|language=ja|page=21}}</ref> (misnamed "Big Boo" in the English manual)<ref>{{cite|date=1993|title=''Yoshi's Safari'' instruction booklet|publisher=Nintendo of America|language=en-us|page=20}}</ref> are enemies in ''[[Yoshi's Safari]]'', where they are encountered only in [[Ghost Mansion]]. Unlike most enemies in the game that can be shot with the [[Super Scope]] to be defeated, shooting a Boo stops it in its tracks. While stunned, [[Yoshi]] can then run into it to defeat it. Defeating a Boo adds 500 points to the player's score (1,000 in Hard Mode), the highest amount of points earned from regular enemies. A [[Big Boo]] serves as the boss for the level.
{{br}}

===''Mario Bros.'' series===
====''Mario Bros.''====
[[File:MBSNES Boo.png|frame|left]]
Boos are enemies in the [[Battle Game (Super Mario All-Stars)|Battle Game]] of the ''[[Super Mario All-Stars]]''{{'}}s ''[[Super Mario Bros. 3]]'' remake. They replace [[Fireball (obstacle)|fireball]]s.
{{br}}

====''Mario Clash''====
[[File:Big Boo Artwork - Mario Clash.png|thumb|Artwork from ''Mario Clash'']]
Boos<ref>{{cite|date=1995|title=マリオクラッシュ (''Mario Kurasshu'') instruction booklet|publisher=Nintendo|language=ja|page=20}}</ref> (misnamed "Big Boo" in the English manual<ref name=ClashBoo>{{cite|date=1995|title=''Mario Clash'' instruction booklet|publisher=Nintendo of America|language=en-us|page=21}}</ref>) are enemies in ''[[Mario Clash]]''. Boos can become transparent and therefore invulnerable, but while opaque, Boos are vulnerable to being defeated by a [[Koopa Shell|Turtle Shell]]. Boos are referred to by feminine pronouns in localized manuals.<ref name=ClashBoo/>

===''Hotel Mario''===
[[File:HM Boo.png|thumb|left|A Boo from ''Hotel Mario'']]
'''Boo Buddies'''<ref>{{cite|date=1994|title=''Hotel Mario'' instruction book|page=16}}</ref> are enemies in ''[[Hotel Mario]]''. Besides behaving similarly as in the platforming games, Boos wander diagonally while the player character is in an elevator. Some other Boos are normally transparent and wander in a similar manner, regardless of where the player character is looking, and sometimes become visible and quickly charge at him.
{{br}}

===''Mario's Picross''===
Boo Diddly is one of the pictures in the "Early Picross" stage in level 6C in ''[[Mario's Picross]]''.

===''Yoshi's Island'' series===
[[File:Bigger Boo SMW2YI Artwork.png|thumb|left|Boos in ''[[Super Mario World 2: Yoshi's Island]]'' have smaller eyes and thinner eyebrows compared to its contemporary depictions, as well as bottom fangs. This design is later used in the first three installments in the ''[[Paper Mario (series)|Paper Mario]]'' series.]]
Boos are enemies in ''[[Super Mario World 2: Yoshi's Island]]'' and [[Yoshi's Island: Super Mario Advance 3|its port]]. They are first encountered in [[World 2 (Super Mario World 2: Yoshi's Island)|World 2]]. Boos can be defeated only by looking away and making an [[Yoshi's Egg|egg]] bounce off of a wall after it is thrown, hitting the ghost in the face. [[Kamek]] turns one Big Boo into [[Bigger Boo]], which serves as a mini boss and grows in size every time he is hit by an egg. The game introduces two variants: [[Boo Balloon]]s, which yield items when they pop, and [[Blindfold Boo|Boo Man Bluff]]s, blindfolded Boos that rely to noise to locate the player character.

Boos appear in both sequels, ''[[Yoshi's Island DS]]'' and ''[[Yoshi's New Island]]'', behaving identically as in ''Super Mario World 2: Yoshi's Island'' and being able to be defeated in the same way as before. In ''Yoshi's Island DS'', there is also a Boo-like midboss in [[Hector the Reflector]]. Boos in ''Yoshi's New Island'' first appear in [[Beware the Boo Brigade]] and retain their laugh from ''Super Mario 64''.

Also, in ''Yoshi's Island DS'', the artwork for Boos shows their modern design, but their in-game sprite still uses their design from ''Super Mario World 2: Yoshi's Island''.
{{br|left}}

===''Super Mario RPG: Legend of the Seven Stars''===
[[File:SMRPG Big Boo Artwork.png|thumb|Artwork from ''Super Mario RPG: Legend of the Seven Stars'']]
Boos return during the events of ''[[Super Mario RPG: Legend of the Seven Stars]]'' and [[Super Mario RPG (Nintendo Switch)|its remake]]. They are misnamed as "The Big Boo" in the original English translation, whereas the remake matches their usual Japanese name and simply calls them Boos. These Boos, like other Boos that appear in previous games, hide behind their arms when stared at. However, some Boos teleport around the room, attempting to scare Mario and his friends. Boos live in [[Kero Sewers]] along with many other ghouls, including [[Hobgoblin]]s and [[Shadow (enemy)|Shadows]]. Often, these three undead monsters will assist each other in battle. Boos have no physical defense, making them extremely weak enemies (for reference, a [[Goomba]] is the weakest enemy encountered and it has three defense points). However, Boos make up for their lack of defense with high evasion, meaning that most attacks against Boos will miss. In battle, Boos command powerful lightning magic, including the attacks [[Lightning Orb]] and [[Bolt (move)|Bolt]]. Boos also know the special attack [[Scream]], which cuts a party member's [[fear|attack and defense in half]]. When not using magic, Boos approach one of Mario's party members and make a face, damaging that character. In this game, there is also a stronger Boo variation called [[High Boo]]s, which are the same size as their normal counterparts but have blue tongues, similar to the first appearance of [[King Boo]]. The only true appearance of a Big Boo in this game is the one used in [[Bowser]]'s [[Terrorize]] attack.<ref>{{cite|date=1996|title=''Super Mario RPG: Legend of the Seven Stars'' instruction booklet|publisher=Nintendo of America|language=en|page=41}}</ref> One Boo lives in [[Monstro Town]] as part of the [[Three Musty Fears]].

===''Super Mario-kun''===
[[File:Boo SuperMarioKun 8.jpg|thumb|left|Boo as it appears in ''Super Mario-kun'']]
Boos appear in some of the ''[[Super Mario-kun]]'' comics. A Boo appears on the cover of volume 16, which is based on ''[[Super Mario 64]]''. Alongside it, [[Eyerok]], a [[Bob-omb]], and [[Bowser]] can be seen. Throughout the comic, they appear, too. Their role in the comic is similar to their role in the game, where they are enemies to Mario and attempt to attack him. [[Lady Bow]], a notable Boo, appears in a couple of the ''[[Paper Mario]]''-based issues. These issues are 25 and 27. Lady Bow appears on the cover of the twenty-fifth issue along with many of [[Mario]]'s other partners, including [[Goombario]], [[Kooper]], [[Eldstar]], and [[Twink]]. Besides appearing on the cover, she appears throughout the comic. Her role in the comic mimics her role in the game. Lady Bow reappears on the cover of the twenty-seventh issue and in the comic. Like in issue 25, Lady Bow's role in the comic is similar to her appearance in the game, where she helps Mario. In a ''[[Super Mario Galaxy]]''-based issue, [[Boo Mario]] appears on the cover along with more of Mario's transformations.
{{br}}

===''Mario Net Quest''===
Ghosts<ref>{{cite|quote=You'll lose points by clicking on Goombahs, Ghosts, or Bowser -- especially Bowser.|date=March 14, 1997|title=''Mario Net Quest''|author=How to Play dialogue|publisher=IBM}}</ref> are obstacles in ''[[Mario Net Quest]]'' that cost the player 1,500 if clicked on. 

===''Yoshi's Story''===
[[File:Yoshis Story Boo.png|thumb|120px|left|A Boo in ''Yoshi's Story'']]
Boos appear in ''[[Yoshi's Story]]''. They are encountered in the stage [[Ghost Castle]]. Boos do not act differently, although they are slightly bigger. Several other Boos variants are encountered in the level, including [[Block Boo]], [[Blindfold Boo]], and [[Mini Boo|Little Boo]]s. Two variations are encountered earlier on in [[Jelly Pipe]], including [[Jelly Ghost]]s and [[Big & Little Boo]]s.

The normal Boo<ref>{{cite|date=February 20, 1998|title=「ヨッシーストーリー 任天堂公式ガイドブック」 (''Yoshi's Story Nintendo Kōshiki Guidebook'')|publisher=Shogakukan|language=ja|isbn=4-09-102619-2|page={{file link|Yoshi Story Shogakukan P7.jpg|7}}}}</ref> is misnamed as a Big Boo<ref>{{cite|author=Leung, Jason, Terry Munson, and Scott Pelland|date=1998|title=''Yoshi's Story'' Player's Guide|publisher=Nintendo Power|language=en-us|page=10}}</ref> in the ''[[Nintendo Power]]'' guide.

===''Game & Watch Gallery'' series===
====''Game & Watch Gallery 2''====
Boo Buddies are enemies in the Modern version of ''[[Vermin]]'' in ''[[Game & Watch Gallery 2]]''. They are encountered either in groups of two or just one. Boo Buddies do not move when looked at.

====''Game & Watch Gallery 4''====
[[File:G&WG4BooSprite.png|frame]]
Boos are enemies in the Modern versions of ''[[Donkey Kong 3 (Game & Watch)|Donkey Kong 3]]'' and ''[[Mario's Cement Factory]]'', as well as the boxing glove of [[Big Boo]] in the Modern ''[[Boxing]]'', in ''[[Game & Watch Gallery 4]]''. The Boo in ''Donkey Kong 3'' slowly approaches [[Mario]] or [[Donkey Kong]] while their backs are turned, scaring the latter to earn the player points, or scaring the former to give the player a miss. Boos in the Modern ''Mario's Cement Factory'' fly into the two containers on the second floor, clogging them up.
{{br}}

===''Mario Party'' series===
Boo has been a major character in the ''Mario Party'' series, from being a thief for hire to being a playable character.
====''Mario Party''====
[[File:CrazyCutter.png|thumb|left|Players cutting out Boos in Crazy Cutter from ''Mario Party'']]
Boos are non-playable characters in ''[[Mario Party]]''. They are encountered in the minigames [[Pedal Power]] and [[Running of the Bulb]], and are a shape featured in [[Crazy Cutters|Crazy Cutter]]. Boos are on every board map except [[Peach's Birthday Cake]], and they provide the player character with the option stealing either a number of coins from an opponent for free or a [[Star (Mario Party series)|Star]] for 50 coins, on their behalf. A Boo is one of the characters to congratulate the victor at the end of [[Luigi's Engine Room]]. A Boo voice can be mimicked by a [[Talking Parrot]].

====''Mario Party 2''====
Boos return in ''[[Mario Party 2]]''. On boards, they function similarly as before. Their role is also integrated into the [[Boo Bell]] item, which summons a Boo. Boo now charges five coins for stealing coins, of which it can take up to thirty of. If the Boo tries to steal Coins, the opponent can fight it off by pressing the A button quickly. Additionally, the Boo can only steal a maximum of 30 coins or a maximum of one Star. A Boo appears in the minigame [[Skateboard Scamper]], going after the player characters, and in [[Day at the Races]] as one of the competitors.

====''Mario Party 3''====
[[File:CurtainCallMP3.png|thumb|Boos in [[Curtain Call]] from ''Mario Party 3'']]
Boos are non-playable characters in ''[[Mario Party 3]]''. One is partnered with [[Yoshi]] by default in [[Mario Party 3#Duel Mode Partners|Duel Mode Partners]]; it counterattacks an opponent (except [[Thwomp]]s) to deliver equal damage, and does this to [[Chain Chomp]] only if it is directly in front. Boos are features on every board, behaving identically as in the previous two games. They are part of the returning Boo Bell item once more. Boos appear in the minigames [[Curtain Call]], [[Stacked Deck]], [[Three Door Monty]], and [[Crowd Cover]]; two portraits of a Boo appear in [[Locked Out]]. Boos have a unique role in [[Waluigi's Island]], where they present two paths to the player character upon being encountered: one of them is rigged and leads to the start, while the other allows the player character to continue along.

====''Mario Party 4''====
[[File: Booparty4.jpg|thumb|x200px|left|The sorcerer Boo from ''Mario Party 4'']]
Boos are represented as characters and species in ''[[Mario Party 4]]''. In both cases, this is the first game to give them a design that they retained in most appearances since. One of the Boos is the host of [[Boo's Haunted Bash]], as well as the fourth host of the Reversal of Fortune. A different Boo is playable in [[Beach Volley Folly]]. Boos appear in [[Long Claw of the Law]], possibly as characters to obtain. The host of Boo's Haunted Bash wears a wizard's hat and cape. Other Boos appear in Boo's Haunted Bash: one owns the Item Shop; another owns the [[Mystery Train]], giving rides to the Boneyard if a [[Red Boo]] is not in its presence; one has the player character press one of the keys of the Horn of Plenty to get one of three randomly chosen items; and one has to press the correct key at the right time until the end of the side game to get a certain amount of Coins. Boos appear on every board, stealing coins and Stars for the player at the [[Ghost House#Mario Party series|Boo House]] similarly to previous entries of the ''Mario Party'' series.

The Boo host also has [[Boo's Game Board|his own board]] in the Flash version of ''[[Mario Party 4 (Flash game)|Mario Party 4]]''.

====''Mario Party-e''====
Boos reappear in ''[[Mario Party-e]]''. They are characters that appear on all of the maps and can steal Coins or a Star from another player on behalf of any player who passes them, where stealing Coins is free, but stealing a Star costs 50 Coins.

====''Mario Party 5''====
Boo is a playable character in ''[[Mario Party 5]]''. It is partnered with [[Koopa Kid]] by default. Boo's previous role on the boards is fulfilled by [[Chain Chomp]].

====''Super Mario Fushigi no Korokoro Party'' series====
In the arcade games ''[[Super Mario Fushigi no Korokoro Party]]'' and ''[[Super Mario Fushigi no Korokoro Party 2]]'', Boo reprises its role as a playable character from ''Mario Party 5''.

====''Mario Party 6''====
Boo is a playable character in ''[[Mario Party 6]]''. Because of this, [[Red Boo]]s take the role of the Boo species, even taking their role in [[Towering Treetop]] and [[Castaway Bay]] at nighttime by allowing player characters to steal coins and stars from opponents.

====''Mario Party Advance''====
{{quote|Ee hee hee! It's ghastly news!|Boo|Mario Party Advance}} 
[[File:MPA Mr E Horror Condo.png|thumb|Boos in the [[Horror Condo]] in ''Mario Party Advance'']]
Boos are non-playable characters in ''[[Mario Party Advance]]''. Four of them haunt [[Boo Cemetery]]. They mention a crime when [[Shroomlock]] appears to assist them, shortly after the player's arrival. At the mention of a theft, the Boos worriedly ask for help to find the [[golden Boo statue]], which they consider a symbol of their friendship. The Boos find that there are four of them instead of the usual three.<ref>{{cite|quote=That's right! We three Boos are best--|author=Boo|date=2005|title=''Mario Party Advance''|publisher=Nintendo|language=en}}</ref><ref>{{cite|quote=When did we pick up a fourth?|author=Boo|date=2005|title=''Mario Party Advance''|publisher=Nintendo|language=en}}</ref> When the Boo with a slightly moveset and rhythm is selected by the player, the false Boo is revealed to be [[Koopa Kid]], who escapes, leaving behind the statue, and the Boos give the player the [[Predictotron]] as a reward. The Boos are said to haunt [[Horror Condo]] regularly in the epilogue.

Boos appear in the minigames [[Boo-Bye]], alongside Red Boos and Blue Boos; [[Spooky Spike]], serving volleyballs to the player character; and [[Floor It!]], as possible passengers to take to the appropriate floor. The [[Porta-Gust]] [[Gaddget]] involves sucking Boos into a vacuum.

====''Mario Party 7''====
Boo is a playable character in ''[[Mario Party 7]]''. It is partnered with [[Dry Bones]]. Red Boos have similar roles as in ''Mario Party 6'' since Boo is playable. Boo's special orb, shared with Dry Bones, is the [[Magic Orb]], which doubles their dice roll and grants temporary invisibility and invulnerability to traps for the next two turns.

====''Mario Party 8''====
Boo is a playable character in ''[[Mario Party 8]]''. Its partner is Dry Bones again. Red Boos take the role of the Boo species once more. [[King Boo]] hosts one of the boards, [[King Boo's Haunted Hideaway]].

====''Mario Party DS''====
Boos are non-playable characters featured in the minigames [[Boo Tag]] and [[Peek-a-Boo (minigame)|Peek-a-Boo]] in ''[[Mario Party DS]]''. A Boo tags a player character in Boo Tag, and player characters try to pass it over to opponents, since the character tagged for the least amount of time is the winner. A variety of Boos appear in Peek-a-Boo, wearing different hats and appearing in a variety of colors like red, blue, green, and yellow. Teams compete to find more wanted Boos more than the opposing side.

====''Mario Party Fushigi no Korokoro Catcher''====
In ''[[Mario Party Fushigi no Korokoro Catcher]]'', Boo reprises its playable role from ''Mario Party 8''.

====''Mario Party 9''====
Boos are featured in the board [[Boo's Horror Castle]] and in the boss minigame [[King Boo's Puzzle Attack]] in ''[[Mario Party 9]]''. There are Boo portraits in Boo's Horror Castle from which a Boo emerges when passed, following behind the player characters by three spaces after each turn. If a Boo is on the same space as the captain, they lose half of their [[Mini Star]]s. Boos are sent out by King Boo in King Boo's Puzzle Attack when he has lost at least half of his health. Only one Boo is present at a time, and it stuns the cursor of a player character on contact.

====''Mario Party Fushigi no Korokoro Catcher 2''====
In ''[[Mario Party Fushigi no Korokoro Catcher 2]]'', during a Golden Jackpot, Boos appear behind Donkey Kong's Floatie alongside King Boo and blink momentarily in a pattern as if they are lights.

====''Mario Party: Island Tour''====
[[File:Boo Artwork (alt) - Mario Party Island Tour.png|thumb|Boo from ''Mario Party: Island Tour'']]
Boo is a playable character in ''[[Mario Party: Island Tour]]''. It holds up a [[Mushroom]] in its artwork.

====''Mario Party 10''====
[[File:King Boo's Tricky Tiles MP10.png|thumb|left|Boss minigame [[King Boo's Tricky Tiles]] from ''Mario Party 10'']]
Boos are non-playable characters in ''[[Mario Party 10]]''. A Boo appears in the board [[Haunted Trail]], where by landing on [[Boo (area)|a certain area]], Boo comes to steal five Mini Stars from a player character with every turn until it either passed to a different opponent from a [[Boo Space]] or driven towards a [[Streetlight]]. Boos appear in the minigames [[Boo Burglars]], as enemies to examine, and [[Balloon Blast Bash]], in the form of a balloon. Several Boos are in the background of [[Luigi Board]].
{{br}}

====''Mario Party: Star Rush''====
[[File:Boo'sBlockParty amiibo.jpg|thumb|Boo's Block Party from ''Mario Party: Star Rush'']]
Boos are non-playable characters in mode Boo's Block Party and in the minigames [[Haunted Hallways]] and [[House of Boos]] in ''[[Mario Party: Star Rush]]''. When a Boo [[amiibo]] is used in Boo's Block Party, four Boos are displayed in the background, two on each screen. Boo can be used in the Mario Shuffle mode if its amiibo is scanned.

====''Mario Party: The Top 100''====
Boos are non-playable characters in the returning minigames [[Slot Trot]] and [[Jigsaw Jumble]] and part of the [[Boo Bell]] item in Minigame Match in ''[[Mario Party: The Top 100]]''.

====''Super Mario Party''====
Boo is a playable character in ''[[Super Mario Party]]''. Its Boo Dice Block consists of two of each -2 coins, 5, and 7.

====''Mario Party Superstars''====
Boos are non-playable characters in every board and in the minigames [[Roll Call (minigame)|Roll Call]] and [[Crazy Cutters]] in ''[[Mario Party Superstars]]''. In boards, Boos steal either coins or stars from an opponent, like in the first three entries of the ''Mario Party'' series.

====''Super Mario Party Jamboree''====
In ''[[Super Mario Party Jamboree]]'' and its [[Nintendo Switch 2]] version, Boo returns as a playable character and a board element, retaining the latter's function from ''Mario Party Superstars''. This is the first game that Boo appears in a playable and non-playable capacity, unlike other games that used other characters for stealing functionalities. If the playable Boo meets the non-playable Boo, the latter will say "Wah! It's like looking into a mirror..."<ref>{{cite|author=God is a Geek|date=September 9, 2024|url=youtu.be/f623bkogUO0?t=466|title=Super Mario Party Jamboree is the biggest entry in the series yet {{!}} Hands-on preview|timestamp=07:46|publisher=YouTube|language=en|accessdate=September 9, 2024}}</ref> and if the latter steals from the former, the latter will say, "Kinda weird, but fun!"

===''Mario Golf'' series===
{{MGTT character infobox
|title=Boo
|image=[[File:ToadstoolTour Boo Mug.png]]
|drive=208 yards
|star_drive=253 yards
|trajectory=Slice
|height=3/5
|impact=13/21
|star_impact=09/21
|control=10/21
|spin=08/21
}}
====''Mario Golf''====
Boos are supporting characters in the [[Mario Golf (Nintendo 64)|Nintendo 64 version]] of ''Mario Golf''. They indicate the wind direction in relation to the camera angle. "Boo" is one of the names that can appear on the scoreboard. A Boo is the basis of the design of hole 2 of [[Mario's Star (golf course)|Mario's Star]]. Boos are depicted in artwork associated with [[Boo Valley]].

====''Mario Golf: Toadstool Tour''====
Boo is an unlockable playable character in ''[[Mario Golf: Toadstool Tour]]''. Besides this, a Boo indicates the wind direction like before. Boos are obstacles in [[Bowser Badlands]], affecting the trajectory of balls hit through them. Two Boos carry a sign and float across the screen slowly if the player delays with their swing; the signs usually describe gameplay tips, but some are taunts.

====''Mario Golf: World Tour''====
[[File:BooHoleInOne.jpg|thumb|left|Boo getting a [[Hole-in-One]] in ''Mario Golf: World Tour'']]
Boo is a playable character in ''[[Mario Golf: World Tour]]''. The wind direction and speed is represented by a blowing cloud instead of a Boo. Boos and King Boo are seen floating in the sky in Hole 4 of [[Bowser's Castle (golf course)|Bowser's Castle]]. 

====''Mario Golf: Super Rush''====
Boo is a playable character in ''[[Mario Golf: Super Rush]]''. Boo is billed a Spin character, having a higher spin stat than the other characters. Its [[Special Shot (Mario Golf: Super Rush)|Special Shot]] is Mischief Twister, which involves several Boos embedding themselves into Boo's golf ball before it swings and later haunting any other balls nearby to force a curved trajectory in their shot gauge. Boo's [[Special Dash]] is the Carousel Dash, in which it is circled and carried forward by Boo Buddies. Boo is not penalized for crossing bodies of water or lava, since it can float, but it does deplete the stamina gauge. Boo appears in Golf Adventure mode as part of the rookie class with the player’s Mii, Toadette, and Chargin’ Chuck. Boo has an variation with a visor available that is unlocked for playing in Ranked Match.

===''Mario Tennis'' series===
====''Mario Tennis''====
[[File:Mt64boo.png|thumb|Artwork from ''Mario Tennis'', the first playable role of Boo]]
Boo is a playable character in the [[Nintendo 64]] version of ''[[Mario Tennis (Nintendo 64)|Mario Tennis]]''. He is billed a tricky character, like with [[Koopa Paratroopa|Paratroopa]]. The [[Mario Tennis (Game Boy Color)|handheld version]] includes a Boo in the [[Boo Blast (minigame)|Boo Blast]] minigame instead, where the goal is to hit Boos, and Boos appear in the audience at [[Peach's Castle]].

====''Mario Power Tennis''====
Boo is also playable in ''[[Mario Power Tennis]]'', which also provides it a different voice. When he wins a championship, Mario and Luigi would come out with the trophy and Boo would be missing. They look around and the trophy would start to float. Boo then appears under it to Luigi's relief as Mario laughs in amusement. The Mario Bros. themselves are then surrounded and levitated by multiple other Boos as the main Boo flies up to the screen and holds the trophy. Boo's taunt is to wave his racket while laughing. Boo's offensive power shot is the [[Boo Blast (move)|Boo Blast]] and defensive power shot is the [[Boo Brigade Return]].

====''Mario Tennis Open'' / ''Mario Tennis: Ultra Smash''====
Boo is a playable character in ''[[Mario Tennis Open]]'' and ''[[Mario Tennis: Ultra Smash]]'', both billing it a Tricky character.

====''Mario Tennis Aces''====
[[File:MTA Models Boo.png|thumb|Boo from ''Mario Tennis Aces'']]
Boo is a playable character in ''[[Mario Tennis Aces]]''. It is billed a Tricky character. There is a co-op challenge titled "Boo Hunt," which can be played to unlock alternate blue, green, and purple visor costumes for Boo, costing 2,500, 10,000, and 20,000 coins, respectively. The challenge involves hitting Boos for coins.
{{br}}

===''Paper Mario'' series===
Boos appear in every game in the ''[[Paper Mario (series)|Paper Mario]]'' series, where they are usually found in ghost houses. In the first three ''Paper Mario'' games, the Boos appear with a design similar to [[Bigger Boo]] from ''[[Super Mario World 2: Yoshi's Island]]''. In the latter three games, they use their modern appearance from ''Mario Party 4'' and onward.
====''Paper Mario''====
{{quote|I want to hear people shriek and watch them run away yelling! That's what makes Boos happy.|Boo|Paper Mario}}
[[File:PM Boos Throwing the Record.png|thumb|Boos in [[Boo's Mansion]] from ''Paper Mario'']]
{{multiple image
|align=right
|direction=horizontal
|image1=PM Boo Sprite.png
|image2=Herbert.png
|width1=38
|width2=39
|footer=Two kinds of Boos from ''[[Paper Mario]]''
}}
Boos appear in ''[[Paper Mario]]'' as friendly but tricky characters. White Boos live in [[Boo's Mansion]], and tan Boos live at [[Gusty Gulch]]. Their leader is [[Lady Bow]], who lives in Boo's Mansion along with [[Bootler]].

At first, Boos were being eaten by [[Tubba Blubba]]. Some Boos tried attacking the monster to save their friends, but they failed because of Tubba Blubba's "Invincibility". Seeking help from [[Mario]], they captured [[Skolar]], the Star Spirit Mario was trying to save, in order to have Mario help them.

In the game, when [[Mario]] arrives at [[Boo's Mansion]], [[Bootler]] tells him to get to the third floor. The Boos have prepared some puzzles for him under the order of [[Lady Bow]] to test him. One puzzle is for Boos to form a rotary circle, throw an item several times and ask Mario to guess who is holding the item. The first time he opens a door a big Boo appears on the screen. In the eastern room of the second floor Boos holding a [[Record (Paper Mario)|Record]] play this trick. In the western room of the second floor, a Boo is guarding a chest box with a [[Weight]] in it. Mario plays the Record to lure the Boo away and uses the Weight on the droplight of the mansion to open the western door on the first floor. Boos in the basement hide in a big chest box in the basement. When Mario opens the chest box, they play the puzzle with [[Super Boots]]. After Mario gets them, he is able to get [[Boo's Portrait]] with which he is able to get to the third floor. There, Lady Bow asks Mario to help the Boos to defeat Tubba Blubba as a condition to free Skolar, and joins Mario's party to assist him. 

A Boo by the name of [[Igor]] also has a shop in the basement, but he will not sell until after Lady Bow joins the party.

In addition, a Boo appears after Mario gets the [[Super Boots]], and tells him how to get the [[Star Piece (Paper Mario series)|Star Pieces]] underground. Additionally, some Boos are flying in the sky who can be seen out of the windows. When Mario is about to set off, two white Boos appear to open the gate to Gusty Gulch under the command of Bow.

In [[Gusty Gulch]], upon [[Tubba Blubba]]'s arrival, the Boos hide except for [[Stanley (Paper Mario)|Stanley]], who is too late and gets caught and eaten by Tubba Blubba.

In the basement of [[Tubba Blubba's Castle]], a brown Boo tells [[Mario]] not to fight [[Tubba Blubba]] until he finds his weak point. According to his word, he sneaked into the castle to look for the weak point. After [[Mario]] gets [[Yakkey]], some tan Boos appear in front of [[Tubba Blubba's Castle]] and, seeing Mario and [[Lady Bow|Bow]] get out and [[Tubba Blubba]] chasing, help the team by blocking the door.

After [[Tubba Blubba]] is defeated, the Boos he has eaten are saved, and Bootler releases Skolar as promised. Boos rejoice, and the background music in Boo's Mansion is replaced with a cheerful one. The Boos at [[Gusty Gulch]] write Lady Bow [[List of letters in Paper Mario#Boos in Gusty Gulch|an admiration letter]], which the player can read at the [[Toad Town Post Office]]. They also begin to talk about a female Boo called [[List of implied characters#Victoria|Victoria]].

After Mario defeats [[Bowser]], two Boos come to [[Peach's Castle]] to see the party, one white and one brown. The white one says he comes to see [[Lady Bow]] in her finery. He thinks that Bow is prettier than [[Princess Peach]]. The brown one says that he is going to have a wedding ceremony after the party. In the end-of-game [[parade]], three white Boos along with [[Bootler]] are carrying [[Tubba Blubba]]'s body.

====''Paper Mario: The Thousand-Year Door''====
[[File:PMTTYD Boo Sprite.png|frame|left]]
Boos return in ''[[Paper Mario: The Thousand-Year Door]]'' and its [[Paper Mario: The Thousand-Year Door (Nintendo Switch)|Nintendo Switch remake]] as friendly characters as well as enemies for the first time in the series. Some Boos such as [[Lahla]] and [[Peeka]] in [[Rogueport]] can be seen running shops and various casino games.
Enemy Boos are found in [[Creepy Steeple]] and levels 21-29 of the [[Pit of 100 Trials (Paper Mario: The Thousand-Year Door)|Pit of 100 Trials]]. When Mario first enters the steeple there is only one Boo in the room who says that he misses his friends. He will let Mario through only one door (blocking him from using any other doors), where he finds a chest. When he opens it, 200 Boos fly out. The last Boo asks Mario "How many Boos came out of that chest?" If Mario answers correctly the Boo will give him an [[Ultra Mushroom|Ultra Shroom]]. If Mario is wrong the Boo will give him one [[coin]]. Upon returning to the main room, the first Boo is still there. He asks if Mario is going to be mean to him. If Mario answers "No", a bunch of Boos (the same ones from the treasure chest) will start flying around the main room, attempting to swarm Mario. If successful, they will throw Mario out of the Steeple, exactly like the [[Sentinel]]s in [[Tubba Blubba's Castle]]. If Mario Spin Attacks them several times, they merge into an [[Big Boo|Atomic Boo]]. Once the Atomic Boo is defeated (releasing a [[Lucky Start]] [[List of badges in Paper Mario: The Thousand-Year Door|badge]]), Mario can fight Boos in other parts of the Steeple. Even before defeating the Atomic Boo, Boos can still be found, but only when accompanying [[Swoop]]ers.

The original Creepy Steeple Boo sends an [[Mailbox SP#Boo: Mail?|e-mail]] to Mario that thanks him for freeing his friends, despite the fact that they attacked him. He signs the letter "[[The Creepy Steeple Boo]]". More Boos can be found in the Pit of 100 Trials. In this game, Boos attack by becoming invisible and getting close to Mario or the partner, then becoming visible and making a glare at them, causing 3 damage. However, if Mario or his allies gets lucky in battle, the Boo who tried to attack Mario and his partner will be tired out. The game also introduces a more powerful sub-species, the [[Dark Boo]], which can be found in [[Poshley Sanctum]].

Boos can also appear as members of the [[audience]], where they can throw items onto the stage and randomly turn a character in the battle invisible for one turn.

In the remake, the Boos use their modern voice clips. Additionally, the Creepy Steeple Boo can be later found in the hidden room containing the [[Cookbook]]. When spoken to, he will quiz Mario again with three questions about various parts of the game, and will reward Mario with an item if the latter answers all three questions correctly. This can be done multiple times, each with its own trio of questions.
======Field Tattle======
Outside of battle, [[Goombella]] can use [[Tattle]] only on a Boo found in the foyer of [[Creepy Steeple]] after Mario releases the 200 Boos.
*"''That's a Boo. You think it's one of the Boos from that box?''"

====''Super Paper Mario''====
[[File:Mansion patrol.png|thumb|Boos in the minigame [[Mansion Patrol]] in the Flipside Arcade from ''Super Paper Mario'']]
Boos return as enemies in ''[[Super Paper Mario]]''. They become invisible if looked at, but if they are not looked at, Boos become opaque and pursue the player character Boos can be defeated by attacking them from behind. Boos, Dark Boos, and Atomic Boos are all featured in the minigame [[Mansion Patrol]], where the goal is to shoot them for points. After being saved from a Boo, a [[Toad (species)|Toad]] often appears to give power-ups. Lady Bow also makes three cameos.

====''Paper Mario: Sticker Star''====
[[File:Boo PMSS.png|frame|left]]
Boos reappear in ''[[Paper Mario: Sticker Star]]''. They only appear in World 4-3: [[The Enigmansion]]. Mario must use the [[Book of Sealing]], given by a [[Toad (species)|Toad]], to seal away every Boo that has escaped. In battle, Boos can make themselves disappear and can slap Mario or they can go up to Mario and scare him by making a scary face. They are able to make Mario [[dizzy]] in this game with their scare attack preventing him from using any of his defensive/dodging stickers. The attack is determined by the sound the Boo makes when it disappears.

Among the normal Boos, there is one golden Boo that drops several Coins after Mario defeats it, which can be found in the safe. This Boo attacks exactly like the normal ones. Another notable Boo is one that is crumpled, which is found in a trash can. In battle, it only has 1 HP and cannot attack. Additionally, a group of eighty-two Boos called a [[Boo Stack]] also appears. Once all the Boos get returned to the book and it is placed in its rightful spot, [[Kamek]] appears and turns all the captured Boos into the mini boss, [[Big Boo#Paper Mario series|Big Boo]]. After defeating the mini-boss, the Boos are put to rest once again and the mansion is restored to its former state. Boos can no longer be fought at this point.

====''Paper Mario: Color Splash''====
[[File:PMCS Boo 10-Stack Idle Animated.gif|thumb|left|A [[Boo 10-Stack]] from ''Paper Mario: Color Splash'']]
Boos return in ''[[Paper Mario: Color Splash]]'' as enemies who can be fought within the [[parallel world]] at [[Vortex Island]], [[Lighthouse Island]] and [[Fortune Island]]. By the time they are first encountered, Mario can instantly defeat them with a hammer [[First Strike]] without entering a battle. In battle, they attack by either hitting Mario or scaring him. They can disappear while in battle, causing all attacks to miss until they reappear. Outside of battle, if one is stared at too long, it will disappear, and then reappear behind Mario. A Boo appears as an NPC in [[Redpepper Crater]], where it is in a hot spring. A [[Boo 10-Stack]] variant also appears.
{{br}}

====''Paper Mario: The Origami King''====
[[File:OrigamiBoo.jpg|thumb|An origami Boo as seen in ''Paper Mario: The Origami King'']]
[[File:Paper Macho Boo.jpg|thumb|left|A Paper Macho Boo]]
[[Folded Soldiers|Origami]] Boos appear as enemies in ''[[Paper Mario: The Origami King]]'', first encountered in the [[Scorching Sandpaper Desert]], but only at night; after Mario has explored the [[Temple of Shrooms]] and put the sun back in the sky, they are replaced by [[Koopa Paratroopa]]s. In battle, Boos will turn invisible right before Mario manipulates the arena, forcing him to memorize their positions. However, they will reveal themselves if they are hit by a Toad's thrown object or shortly before time runs out. In addition, much larger [[Paper Macho Boo]]s appear in the desert at night, replaced by [[Paper Macho Koopa Paratroopa]]s by day. A Paper Macho Boo is also featured as one of the seven opponents on [[Scuffle Island]].
{{br}}

===''Luigi's Mansion'' series===
====''Luigi's Mansion''====
{{main|List of Boos in Luigi's Mansion}}
[[File:LMBoo.jpg|thumb|left|A Boo in ''Luigi's Mansion'']]
Boos are enemies in ''[[Luigi's Mansion]]'' and [[Luigi's Mansion (Nintendo 3DS)|its remake]]. This is the first appearance of [[King Boo]], the main antagonist as well as leader of the [[List of Boos in Luigi's Mansion|50 Boos]]; of the Boos, 15 of them are [[Mini Boo|smaller one]]s that make up the portrait ghost [[Boolossus]]. Boos appear in rooms even while the lights are on, unlike with other ghosts. When a Boo is attacked, it usually flees, but some twirl into Luigi to cause damage.

====''Luigi's Mansion: Dark Moon'' / ''Luigi's Mansion 2 HD''====
{{main|List of Boos in Luigi's Mansion: Dark Moon}}
Boos are enemies in ''[[Luigi's Mansion: Dark Moon]]'' and ''[[Luigi's Mansion 2 HD]]''. There are a total of [[List of Boos in Luigi's Mansion: Dark Moon|32 Boos]], all serving [[King Boo]], who returns as the main antagonist; ten of the Boos merge into the [[Big Boo]] fought in the [[Treacherous Mansion]]. The regular Boos all have names that play on "Boo," like in the previous game. Every mission has a Boo hidden in an invisible object that can be revealed only from using the [[Dark-Light Device]]. Once all five Boos are caught in a mansion, a bonus mission for it is unlocked. Boos can create [[Spirit Ball]]s, which make objects invisible, and appear from certain ones only after [[Luigi]] has vacuumed all of them in. A Boo is captured by pulling back on its tongue using the [[Poltergust 5000]] and releasing it by pressing {{button|3ds|A}}, damaging the Boo as it bounces around the room. When it reaches 0 [[Heart Point|HP]], the Boo can be forced into the Poltergust 5000 when attached to the nozzle and shoved inside by Luigi. All captured Boos are located in the Boo Canister in the [[E. Gadd's Vault#Boo Canister|Vault]], each being sent down there after Luigi returns to the [[Lab|Bunker]] from a mission.

====''Luigi's Mansion 3''====
{{main|List of Boos in Luigi's Mansion 3}}
[[File:LM3BooArt.jpg|thumb|175px|A Boo in ''Luigi's Mansion 3'']]
Boos are enemies in ''[[Luigi's Mansion 3]]''. Like in previous entries, their names often include "Boo" in it. [[King Boo]] returns as the main antagonist. There is a Boo to catch on every floor except the [[Master Suite]], and a Boo appears on a floor randomly once Luigi has retrieved the [[elevator button]] of that floor. Whenever a Boo is in the room next the player characters, [[Gooigi]] vibrates, as well as the player's controller. One Boo can be located with each [[Boo Finder]]. The music is different in a room with a Boo, which is in the object that vibrates the strongest. The Boo launches a swarm of bats at Luigi if he uncovers the wrong object before fleeing into a different room. A Boo attacks by either spinning towards Luigi to deduct 20 HP or by throwing a [[Bomb (object)|bomb]] at him. When revealed, the Boo has to be caught before Luigi can leave the room. Boos are caught the same way as in ''Luigi's Mansion: Dark Moon'', though every Boo now has 20 HP.

===''Super Smash Bros.'' series===
{{main-wiki|SmashWiki|Boo}}
In the [[Super Smash Bros. (series)|''Super Smash Bros.'' series]], Boos mostly appear in the form of collectible items. In ''[[Super Smash Bros. Melee]]'', a Boo appears as a collectible [[Trophy (Super Smash Bros.)|trophy]]. In ''[[Super Smash Bros. Brawl]]'', there is another trophy of Boo, as well as a [[Sticker (Super Smash Bros. Brawl)|sticker]] depicting its artwork from ''Mario Tennis''. In both ''[[Super Smash Bros. for Nintendo 3DS]]'' and ''[[Super Smash Bros. for Wii U]]'', Boos once again received their own collectible trophy; furthermore, ''Super Smash Bros. for Wii U'' gave one an item in {{iw|smashwiki|Smash Tour}}, where using it allows the player to begin a battle while invincible. In ''[[Super Smash Bros. Ultimate]]'', there is a Novice-class Neutral-type primary [[Spirit (Super Smash Bros. Ultimate)|spirit]] of a Boo, using its artwork from ''[[New Super Mario Bros. U]]'', and it can be enhanced to [[King Boo]] at level 99. In [[smashwiki:Adventure Mode: World of Light|World of Light]], the Boo spirit appears in the [[smashwiki:Dracula's Castle (World of Light)|Dracula's Castle]] sub-world of the {{iw|smashwiki|Dark Realm}}. The spirit battle takes place on the [[Mushroom Kingdom U]] stage, with an invisible grayscale [[Kirby]] as the puppet fighter.

Boos appear in the background of the [[Luigi's Mansion (stage)|Luigi's Mansion stage]] in ''Super Smash Bros. Brawl'', ''Super Smash Bros. for Wii U'', and ''Super Smash Bros. Ultimate''. Here, they are very briefly seen flying out the [[Luigi's Mansion (location)|mansion]] when a part of it is knocked down.

===''WarioWare'' series===
Boos appear in the [[Mario Clash (microgame)|Mario Clash]] microgame in ''[[WarioWare, Inc.: Mega Microgame$!]]'' and ''[[WarioWare Gold]]'', exclusively in the second level. The only other microgame they appear in is [[Boo (microgame)|Boo]] in ''[[WarioWare: D.I.Y. Showcase]]'', which involves starting at both Boos without touching them.<ref>{{cite|quote=Keep the Boos at bay. By looking.|date=2009|author=In-game instructions|title=''[[WarioWare: D.I.Y. Showcase]]''|publisher=Nintendo|language=en}}</ref>

===''Mario & Luigi'' series===
====''Mario & Luigi: Superstar Saga'' / ''Mario & Luigi: Superstar Saga + Bowser's Minions''====
[[File:Castleinterior.png|thumb|A Boo chases the Mario Bros. in ''Mario & Luigi: Superstar Saga''.]]
Boos are enemies exclusive to [[Bowser's Castle]] in ''[[Mario & Luigi: Superstar Saga]]''. As usual, Boos hover in Mario and Luigi's direction when they are faced away but look away if they are looked at. For its turn, if a Boo makes a face, it targets Luigi, but goes after Mario otherwise. During battle, the Boo can attack by either teleporting in front of Mario or Luigi and to try and bite him or by flying up and swooping at him, possibly [[Prohibited Command|prohibiting the use of certain moves or items]]. The former attack can be countered with a [[hammer]] and the latter dodged or countered with a jump. Boos are weak to [[Firebrand]] and [[Fire Bros. (move)|Fire Bros.]] Boos have low HP but very high defense.

[[File:MLSS Miner Boo.gif|frame|left]]
Boos are in levels 4 and 5 of [[Mysterious Mine Carts]] (levels 3 and 5 in the remake). They wear mining helmets and brandishing pickaxes. If they touch Mario, he loses a diamond. Boos slowly shrink until disappearing by pointing a flashlight at them.

[[File:Boo Statue M&LSS sprite.png|frame|right]]
There are also [[Boo Statue]]s which become invisible and cannot be interacted with when looked directly at. Mario and Luigi must use the [[Tickle]] move to push them while facing backward.

The [[Boo Biscuit]] item appears only in the [[Mario & Luigi: Superstar Saga + Bowser's Minions|remake]]. Additionally, for the ''[[Minion Quest: The Search for Bowser]]'' mode, Boos appear as flying troopers. Their evasion can be increased from their [[Special Skill (Mario & Luigi series)|Special Skill]], Evasion Cloak, based on how much the corresponding meter is filled. Boos attack by ramming into enemies. [[Captain Boo]] is also a playable caption, and Big Boo and [[Tail Boo]] also return. As a captain, Boo can attack the other captain from behind, using [[Sneak Attack]].

====''Mario & Luigi: Partners in Time''====
[[File:PiT Boo.gif|frame]]
During the events of ''[[Mario & Luigi: Partners in Time]]'', Boos appear in [[Bowser's Castle (Mario & Luigi: Partners in Time)|Bowser's Castle]] of the past. Their [[Dark Boo]] varieties also appear, in the [[Gritzy Caves]]. Outside of battle, Boos behave the same as before, though they behave differently in battle. Before attacking, Boo chooses target either Mario if its right eye is pointed at him or at Luigi with its left eye.<ref>{{cite|quote=If he opens his right eye he’ll attack Mario: an open left eye means Luigi will be the target.|author=Hoffman, Chris|date=November 18, 2005|title=''Mario & Luigi: Partners in Time'' Player's Guide|publisher=Nintendo of America|language=en-us|isbn=1-59812-006-9|page=19}}</ref> Afterward, Boo appears behind its target and charges, although its attack can be either dodged or countered with a jump. While battling [[Sunnycide]], if it is on its back, Sunnycide can summon a Boo to attack Mario or Luigi,<ref>{{cite|quote=When the Yoshis knock Sunnycide on its back, it'll sometimes turn out the lights and send out a Boo.|author=Hoffman, et al.|title=''Mario & Luigi: Partners in Time'' Player's Guide|language=en-us|page=42}}</ref> who can counter using their hammer. While battling a [[Handfake]], if it has a [[Bowser]] sign, either Boo or a [[Fly Guy]] carries a flame from Bowser's mouth.

====''Mario & Luigi: Bowser's Inside Story'' / ''Mario & Luigi: Bowser's Inside Story + Bowser Jr.'s Journey''====
[[File:Bis Boo plate sprite.PNG|frame|left|A Boo holding a plate]]
{{multiframe
|[[File:BowserMemoryBoo.png]] [[File:MLBISBJJBowserMemoryBoo.png]]
|A digital Boo.
|align=right
|size=75
}}
Boos appear in [[Bowser's Castle]] in ''[[Mario & Luigi: Bowser's Inside Story]]''. They and the rest of [[Bowser's Minions|Bowser's minions]] have served Fawful ever since he took over the castle. One of the Boos is shown to be in love with a [[Koopa Troopa]] and vice versa if spoken to. Three Boos later force-feed Bowser lots of food after he defeats [[Midbus]], followed by Bowser becoming trapped in floor from his weight. Later on, Boos are among the brainwashed minions who push the Fawful statue against Bowser. When Bowser levels up, a Boo is shown holding the circle when choosing a bonus stat upgrade.

[[Yikk]], a ghost who appears in the same game at the [[Tower of Yikk]], explains that he researches Boos. He even builds a [[Boo-ray Machine|machine]] to visualize Boo transparency waves before he passed away.

During the fight with [[Bowser Memory M and Bowser Memory L]], the latter has an attack of being chased around by a digital Boo. The Boo can be jumped on by either brother to stop the attack prematurely.

[[File:MLBISBJJBoo.png|frame]]
Boos return in [[Mario & Luigi: Bowser's Inside Story + Bowser Jr.'s Journey|the remake]], as well as Boo Biscuits, which are not in the base game. Additionally, they are enemies and recruitable allies in the ''[[Bowser Jr.'s Journey]]'' mode. Their Special Skill is Discord, which [[SPD-Down|lowers the speed]] of enemies. Captain Boo also returns as well as Big Boo and Tail Boo.

====''Mario & Luigi: Dream Team''====
[[File:M&LDT Boo Biscuit.png|frame|left]]
Boos are referenced in ''[[Mario & Luigi: Dream Team]]''. The game features an item named [[Boo Biscuit]].

Additionally, the [[Mad Skillathon]]'s version of the [[Bomb Derby]] [[Bros. Attack]] has bombs with Boos printed on the design. These bombs will vanish in the middle of their flight path towards [[Mario]], so he has to time his swing to send the bomb at the target. (The flight time is identical to the regular bombs.) These bombs are worth five points.

====''Mario & Luigi: Paper Jam''====
[[File:MLPJShinyPaperBoo.png|frame|left]]
Boos are featured in a minigame of ''[[Mario & Luigi: Paper Jam]]'' where the player has run from a Boo while avoiding firebars and bombs to save a Toad. Boos retain their usual trait of pursuing while not looked at but covering their face if they are. Boos are also seen carrying Papercraft Boos, along with Papercraft King Boo. Boos also have [[Paper Boo|paper counterparts]], which are encountered in [[Gloomy Woods]], as well as [[King Boo]]. Boo Biscuits also return from ''Mario & Luigi: Dream Team''.
{{br}}

====''Mario & Luigi: Brothership''====
Boos appear in ''[[Mario & Luigi: Brothership]]'' as enemies in Bowser's Castle. In battle, Boos form into Boo Buddies and circle above a bro. while slowly descending, similar to [[Paper Boo|their paper counterparts]] in the previous game. The bro must jump on at least one Boo to end the attack. Boos can also create clones and each move towards the bros. The clones disappear before reaching the bros. but the real Boos must be countered with the hammer. Boos can call for backup if there are not many left, including different enemies that had been defeated in the same battle. A Boo is of Level 32. [[Boo Biscuit|Boo Biscuits]] also reappear, serving the same purpose as before and can be used in the fight against the [[Extension Corps]] to negate the effects of their [[Battle Plug]] at the end of the fight.

During the side quest [[Feelings of Dread]], Mario and Luigi find an elderly woman on [[Shipshape Island]] who directs them to [[Nanoh Islet]]. Mario and Luigi find a Boo there and must defeat it in battle. Mario and Luigi then report back to the elderly woman, who reveals herself to be a Boo in disguise and leaves.

A [[Glohm]]-contaminated version of the Boo can be found later in the game, inside the hanger of the fortress [[Bowser]] and his army set up on [[Wayaway Island]]. These "[[Glohm Boo]]s" become more numerous when [[Reclusa]] goes on a rampage after being resurrected by [[Zokket]], and explode in a wave of fire that must be avoided when defeated.

===''Mario vs. Donkey Kong'' series===
====''Mario vs. Donkey Kong''====
{{multiframe
|[[File:MvsDK Boo.png]]<br>[[File:MvDKNSBoo.png|100px]]
|align=left
}}
Boos are enemies in ''[[Mario vs. Donkey Kong]]'' and [[Mario vs. Donkey Kong (Nintendo Switch)|its remake]]. They act similarly to their appearances in platforming games. Boos appear in both segments of [[Level 5-4 (Mario vs. Donkey Kong)|Level 4-4]] and in [[Level 5-4+|Level 4-4+]] only. Boos cannot be defeated, and they grow and stick their tongue out if they defeat [[Mario]] or a [[Mini Mario (toy)|Mini-Mario]]. The remake depicts Boos with a more toylike appearance, and Boos float towards [[Toad]] in co-op play if his back is turned away, but stop moving if looked at.<ref>{{cite|author=NintendoEurope|date=January 26, 2024|title=Find out if two heads really are better than one in #MarioDonkeyKong's new co-op mode! Pass a controller to a friend and tackle the puzzle-platforming challenges together (and let Toad get a bit of glory too!).|url=x.com/NintendoEurope/status/1750866179407655354|publisher=X|accessdate=February 1, 2024}}</ref>

====''Mini Mario & Friends: amiibo Challenge''====
{{multiple image
|align=right
|direction=horizontal
|footer=Boos in their active and inactive states in ''Mini Mario & Friends: amiibo Challenge''
|image1=MM&FaC boo on.jpg
|width1=41
|image2=MM&FaC boo off.jpg
|width2=76
}}
Boos are enemies in ''[[Mini Mario & Friends: amiibo Challenge]]''. They are depicted with a toylike design. Boos appear in every level of [[Moonlight Mansion]], as well as levels [[Star 3]] and [[Star 5]] in the [[Star World (Mini Mario & Friends: amiibo Challenge)|Star World]]. Boos float in mid-air, with some of them staying in a single position and others moving back and forth horizontally or vertically. Boos are invincible. They become harmless if they enter the light coming from a [[Candle]], making it possible for the [[Mini]]s to bypass them as the Boos stop in place and cover their eyes.

===''Mario Pinball Land''===
Boos are enemies in ''[[Mario Pinball Land]]''. [[Big Boo]] is one of the bosses. A Boo is defeated if hit from behind, rewarding 2,000 points. A Boo becomes transparent if Mario tries to pass through it and does not take damage. Boos sometimes vanish and reappear elsewhere in the area.

===''Dance Dance Revolution: Mario Mix''===
Boos are obstacles in ''[[Dance Dance Revolution: Mario Mix]]''. Boos try to get the player character to miss a step, blocking his next move if successful. Boos can be held back if the stepped on, unlike their gigantic counterparts.

===''Mario Baseball'' series===
[[File:Boo-Batting-MSS.png|thumb|left|Boo prepares to bat in ''Mario Super Sluggers'']]
Boo is playable in ''[[Mario Superstar Baseball]]''. It is on Wario's team as a starter. Boo is tied with Peach with its pitching, losing only to [[Bowser]] and [[Waluigi]]. Its special running and fielding move is a [[Super Jump (Mario Baseball series)|Super Jump]]. Its running and batting are weak, but its fielding is very poor. The only worse fielder in the game is [[Bowser]].

Boo makes another appearance in ''[[Mario Super Sluggers]]''. It is on Wario's team once again, and it can be unlocked in [[Wario City]] by finding it in between boxes and completing its challenge. Like its predecessor, Boo has the highest ranked pitch in the game, along with Peach (9/10). Despite its pitching being very high, its stamina is very poor, but its other stats range from average to low. Boo displays good chemistry with [[King Boo]], [[Shy Guy]], [[Magikoopa]], and [[Blooper]]. It has bad chemistry with [[Mario]], [[Luigi]], [[Yoshi]], [[Baby Mario]], [[Baby Luigi]], [[Baby Peach]], and [[Baby Daisy]].

There is a new item named [[Mini Boo]]s that, when activated, turn the ball invisible for a short period of time. If used against a computer, the player stops moving until the Boos go away. If used when a special hit is in effect, the Boos do nothing.
{{br}}

===''Super Princess Peach''===
[[File:SPPBoo.png|frame]]
Boos are enemies in ''[[Super Princess Peach]]''. Boos behave like they do in ''Super Mario Bros. 3''. Besides the returning Big Boos and [[Blindfold Boo]]s, the game introduces an angry variety, [[Mad Boo]]. King Boo also returns as a boss.

===''Mario and the Incredible Rescue''===
[[File:MarioAndIncredibleRescue.jpg|thumb|120px|Two Boos appear on the front cover of ''Mario and the Incredible Rescue'']]
Ghosts, as they are called generically, are enemies in ''[[Mario and the Incredible Rescue]]''. Two of them are displayed on the cover, one depicting its artwork from ''[[Mario Kart: Super Circuit]]'' and the other from ''[[Luigi's Mansion]]''. Ghosts capture [[Princess Peach]] and take her to [[Bowser's Castle]], and Mario has a vision of six ghosts surrounding her. The ghosts are defeated eventually from a spell cast on them, sending them flying out of the castle.
{{br}}

===''Mario Hoops 3-on-3''===
Boo is an unlockable playable character in ''[[Mario Hoops 3-on-3]]''. It is billed as a Tricky player. Boo's special ability is the [[Thriller Dunk]]. Boo can be unlocked by completing the [[Flower Tourney]] on hard difficulty.

===''Mario Strikers Charged''===
{{quote|This ghost can fly up and down the sidelines with great speed, using precise and accurate passing to lead his team to victory. His long-distance shots are quite weak though and his hits are not very powerful. If Boo gets a chance, he can Possess the ball and score at will.|Description}}
[[File:Boo Orange Yoshi MSC.jpg|thumb|left|Boo from ''Mario Strikers Charged'']]
Boos are sidekicks in ''[[Mario Strikers Charged]]''. They wear a helmet with the logo of their team captain. Boos are classified as a playmaker, like [[Toad (species)|Toads]]. They have [[Possess]] as their skillshot.
{{br}}

===''Mario & Sonic'' series===
{{multiframe|align=left|[[File:BooMASATOG.png]]|size=130|A sprite of a Boo from the Nintendo DS version of ''Mario & Sonic at the Olympic Games''}}
In the [[Mario & Sonic (series)|''Mario & Sonic'' series]], Boos mainly appear in a few events, sometimes also as audience members. In the [[Wii]] version of ''[[Mario & Sonic at the Olympic Games (Wii)|Mario & Sonic at the Olympic Games]]'', Boos appear as an item in [[Dream Race (Mario & Sonic at the Olympic Games for Wii)|Dream Race]], where they temporarily follow whoever is in first place, or second if the player in the lead uses it, causing them to lose speed. It is possible for multiple Boos to follow a character at once, causing them to remain at a lower speed, but a [[High Speed]] item can remove them. In the [[Mario & Sonic at the Olympic Games (Nintendo DS)|Nintendo DS version]], Boos penalize the player if they perform two consecutive fouls in the [[100m (Mario & Sonic at the Olympic Games for Nintendo DS)|100m]], [[400m (Mario & Sonic at the Olympic Games for Nintendo DS)|400m]] or [[400m Hurdles (Mario & Sonic at the Olympic Games for Nintendo DS)|400m Hurdles]] events, and in [[Dream Basketball]], a Boo blocks one of the baskets if a [[Chaos Emerald]] is used. Both versions of ''Mario & Sonic at the Olympic Games'' include Boos as part of the audience in various events. In the Nintendo DS version of ''[[Mario & Sonic at the Olympic Winter Games (Nintendo DS)|Mario & Sonic at the Olympic Winter Games]]'', Boos are items in three events: [[Ski Cross Racing]], where they can steal [[Ring (Sonic the Hedgehog)|Rings]] and items from players ahead of the user; [[Extreme Snowboarding]], where Boos steal items from opponents in front and deplete the energy in their trick gauge; and [[Ski Shooting]], where Boos will simply steal an item from an opponent if they have any. In the Nintendo 3DS version of ''[[Mario & Sonic at the Rio 2016 Olympic Games (Nintendo 3DS)|Mario & Sonic at the Rio 2016 Olympic Games]]'', Boos appear in [[Archery Plus]], where they carry around the targets and disappear upon being shot.

Boos appear in some of the minigames. In the Nintendo DS version of ''Mario & Sonic at the Olympic Games'', Boos appear in two minigames: [[Conveyor Belt (minigame)|Conveyor Belt]], as one of the characters needing to be sorted, and [[Shoot!]], as one of the enemies to be hit. In ''[[Mario & Sonic at the London 2012 Olympic Games (Wii)|Mario & Sonic at the London 2012 Olympic Games]]'', Boos also appear in some minigames in the London Party mode, which itself has some Boos that can be spoken to play minigames and earn stickers.
[[File:M&S 2012 The Ghostly Tower.png|thumb|King Boo talking to a Boo in [[The Ghostly Tower]]]]
Boos have also had some of their own collectible items. In the Wii version of ''Mario & Sonic at the London 2012 Olympic Games'', one of the unlockable [[Mii]] outfits is a jersey featuring a Boo design. In the [[Nintendo 3DS]] version of ''[[Mario & Sonic at the London 2012 Olympic Games (Nintendo 3DS)|Mario & Sonic at the London 2012 Olympic Games]]'', a [[List of badges in Mario & Sonic at the London 2012 Olympic Games (Nintendo 3DS)|badge]] of a Boo can be obtained from the badge machine.

In [[Nintendo 3DS]] version of ''[[Mario & Sonic at the London 2012 Olympic Games (Nintendo 3DS)|Mario & Sonic at the London 2012 Olympic Games]]'', a Boo first appears in the Story Mode trying to scare people away from the [[Tower of London]] with the [[Phantasmal Fog]], and is then followed by [[Sonic]] and [[Tails]] who challenge the Boo and King Boo to an Olympic [[Event]], with the Boos fleeing when they lose. A single Boo also appears at the opening ceremony. A Boo also appears in [[Mario's Defeat?!]], in which it fails to bring Mario to the [[London Tennis Club]] but helps set up the match with a Goomba transformed to look like Mario, and later celebrates with the other minions when they notice that Bowser seems to be back to his usual self.

===''Mario Sports Mix''===
Boos are non-playable characters in ''[[Mario Sports Mix]]''. They are encountered during [[Mario Sports Mix#Basketball|Basketball]] and [[Mario Sports Mix#Volleyball|Volleyball]] matches in [[Luigi's Mansion (location)#Mario Sports Mix|Luigi's Mansion]], where Boos circle around the court. Boos make laughter sounds, especially when a player character scores.

===''Captain Toad: Treasure Tracker''===
[[File:TreasureTracker-E32014-Screenshot11.png|thumb|A shy Boo in ''Captain Toad: Treasure Tracker'']]
Boos return in ''[[Captain Toad: Treasure Tracker]]'' and [[Captain Toad: Treasure Tracker (Nintendo Switch / Nintendo 3DS)|its ports]]. They are mostly the same as in ''Super Mario 3D World'', but with some differences. Boos and [[Big Boo]]s can be defeated quickly using either Toad's or Toadette's headlamp. Boos disappear while interacted with on the touch screen or with the pointer functionality; this does not reward any [[coin]], unlike most enemies.

===''Mario Sports Superstars''===
[[File:Card SuperRare Boo.png|thumb|left|A Super Rare Boo card from ''Mario Sports Superstars'']]
Boo is a playable character in ''[[Mario Sports Superstars]]''. This Boo is a starter captain-type who is billed a Technique player, giving it an advantage in accuracy or horse control, except in tennis, which bills it a Tricky type. Boo's rallies curve in tennis, making the trajectory of its shots less predictable. Boo has a default drive of 213 yards and shots that travel medium-low in a draw trajectory in golf.

===''Mario + Rabbids'' series===
====''Mario + Rabbids Kingdom Battle''====
[[File:MoonlightSonata MarioRabbids.png|thumb|A Boo in [[Moonlight Sonata]] from ''Mario + Rabbids Kingdom Battle'']]
Boos are obstacles in ''[[Mario + Rabbids Kingdom Battle]]''. They warp to certain areas during the turn transition between the heroes and enemies. If a Boo converges on a character, it will follow said character and force them to warp to a random spot on the battlefield along with the Boo. Additionally, one of [[Rabbid Mario]]'s Melee weapons has a design based on a Boo, and in [[Spooky Trails]], several Boos can be found ensnared by ghostly chains, as well as a [[Boo Balloon]] that was merged with a [[Rabbid]] and a phonograph, becoming the [[Phantom (boss)|Phantom]].

====''Mario + Rabbids Sparks of Hope''====
While no Boos appear in ''[[Mario + Rabbids Sparks of Hope]]'', the laugh of one can be heard if the [[Spark (Mario + Rabbids Sparks of Hope)|Spark]] [[Vampastra]] applies its Vamp Attack ability to Mario, and he uses his Dual Slingers to attack. In the [[Rayman in the Phantom Show]] DLC, Boos make cameos as the Spooky Trails banners from the first game.
{{br}}

===''Dr. Mario World''===
[[File:DMW Dr Boo Artwork.png|thumb|left|Artwork of Dr. Boo in ''Dr. Mario World'']]
Boos are assistants in ''[[Dr. Mario World]]'' as of October 31, 2019. Its effect in stage mode is to fill the skill meter faster when yellow [[virus]]es are eliminated, where it fills more at higher levels. The percentage determines the number of points the skill meter fills, so for example at level 3, it fills 30% faster, meaning that for each yellow virus eliminated, an extra 0.3 points is added to the skill meter. In versus mode, its effect is to increase the speed the skill meter fills for both the user and their opponent, in which the amount of points required to fill the skill meter is reduced by the listed percentage. If both players use this assistant, the effect stacks. The resulting amount of points required to fill the skill meter is rounded down to the nearest round number.

A Boo was added as a doctor under the name '''Dr. Boo''' on September 24, 2020. His skill is represented by the Boo shielding his face, after which he shows his face and tongue. In stage mode, he immediately eliminates objects in a random 2 x 2 area, similar to [[Fire Mario|Dr. Fire Rosalina]]'s skill but it affects a smaller area. In versus mode, he eliminates objects in a 1 x 1 area at level 1, a 2 x 2 area at level 2 and a 3 x 3 area at level 3 to 5 (the skill meter fills faster at higher levels). This skill prioritizes areas that contain [[virus]]es, but if there are no more viruses, the area in which is targeted will be random as long as it contains at least one object.

===Other appearances===
====''The Legend of Zelda: Link's Awakening''====
{{main-wiki|ZeldaWiki|Boo|Zelda Wiki}}
[[File:TLOZ LA remake Boos.jpg|thumb|Boos as they appear in the remake of ''The Legend of Zelda: Link's Awakening'']]
Boos in ''[[The Legend of Zelda: Link's Awakening]]'' only appearing in a dark room in the games' second dungeon, [[zeldawiki:Bottle Grotto|Bottle Grotto]]. They actively chase [[Link]] regardless of whether he is facing them or not; if Links swings his sword at them, they disappear and reappear at a different location. After Link lights up the room, they become vulnerable and can then be defeated with [[zeldawiki:Magic Powder|Magic Powder]]. In the [[Nintendo Switch]] remake of the game, they now use their voice clips from the ''Super Mario'' franchise, and a Boo figure can be won from the [[zeldawiki:Trendy Game|Trendy Game]] after clearing the [[zeldawiki:Key Cavern|Key Cavern]] and placed in the [[zeldawiki:Quadruple|Quadruples]]' house. The text that appears upon acquiring the figure reads, "''You got a Boo figure! As spooky ghosts go, this one's pretty cute!''"

====''Minecraft''====
[[File:Minecraft Mario Mash-Up Boo.jpg|thumb|left|Boo as it appears in ''Minecraft'']]
Additionally, in the Super Mario Mash-Up Pack in ''[[Minecraft]]'', Ghasts are replaced by Boos.

====''Monopoly Gamer''====
Boo is a playable character in ''[[Monopoly Gamer]]''. It is sold separately as a "Power Pack" expansion figure.
{{br|left}}

====Nintendo Music====
{{main|List of playlists with Super Mario tracks on Nintendo Music#Boo}}
[[File:Boo Playlist.png|thumb|175px|The "Boo" playlist's cover]]
Since October 31st, 2024, the [[Nintendo Music]] app has featured a Boo playlist. {{:List of playlists with Super Mario tracks on Nintendo Music|transcludesection=Boo}} In addition to hosting tracks themed around Boos, the Boo playlist also contains tracks themed around the character [[King Boo]].

===Unused appearances===
====''Super Mario Odyssey''====
Boos [[List of Super Mario Odyssey pre-release and unused content|were going to appear physically]] in ''[[Super Mario Odyssey]]'', as one is seen in concept art for the game, but they were removed from the game,<ref>{{cite|author=Brian|date=October 3, 2018|title=New Super Mario Odyssey concept art shows a ton of scrapped costume ideas|url=nintendoeverything.com/new-super-mario-odyssey-concept-art-shows-a-ton-of-scrapped-costume-ideas/|publisher=Nintendo Everything|language=en}}</ref> making this game the first game in the ''Super Mario'' series to not contain Boos since ''[[Super Mario Land]]''. However, [[Princess Peach|Peach]] wears a Boo mask on the side of her head when she visits [[Bowser's Kingdom]], a common way to wear masks of ''{{wp|yōkai}}'' in festivals in Japan.

====''The Super Mario Bros. Movie''====
Boos were planned to appear in the film, as they can be seen in early concept artwork for the [[Dark Land]]s, but they were removed from the final release.<ref>{{cite|author=GameXplain|date=April 23, 2023|title=Toadsworth & Toadette were in the Super Mario Bros. Movie?! Concept Art LEAK Reveals Cuts & Changes|url=www.youtube.com/watch?v=b2KZXJg3ncA|publisher=YouTube|language=en|accessdate=April 23, 2023}}</ref> However, their leader, [[King Boo]], makes an appearance during the wedding between [[Bowser]] and [[Princess Peach|Peach]].

==General information==
===Physical appearance===
[[File:Boo art04.png|thumb|left|A laughing Boo with a shy Boo]]
{{multiframe
|[[File:Boo model SMBW.png|100px]][[File:Bigger Boo SMW2YI Artwork.png|100px]][[File:LMBoo.jpg|100px]][[File:SMS Boo Artwork.jpg|100px]]
|(Clockwise from the top left) The Boo's ''Super Mario Bros. Wonder'' design, the ''Super Mario World 2: Yoshi's Island'' design, ''Super Mario Sunshine'' design, and ''Luigi's Mansion'' design
|size=200
|align=right
}}
Though their specifics change from game to game, Boos are usually bashful, cowardly, spherical ghosts. They have black beady eyes and fangs. Although they are typically white, there are sub-species of the Boo race that appear in different colors, such as [[Red Boo|pink]]. From ''[[Luigi's Mansion]]'' onward, it became common to picture Boos sticking out their tongues. Boos often have wide open grinning mouths with their tongue sticking out. In most games, Boos are unable to change their facial expressions. The only exception is when they are looked at, in which case they bashfully cover their faces along with the section around their eyes blushing red or pink. However, the ''Luigi's Mansion'' and early ''Paper Mario'' games portray Boos as being more expressive than in other games, being able to frown, scowl, or even smirk. Since ''[[Super Mario 64]]'', Boos have been portrayed with a unique, high-pitched laugh. Both this laugh and [[Bowser]]'s laugh are derived from the same stock recording of a human man laughing recorded by [[Charles Martinet]];<ref>{{file link|Charles Martinet and the Comical Laugh Pt 2.png}}</ref> it was sped up for the Boos and slowed down for Bowser. However, Boos received a new laugh starting in ''[[Mario Power Tennis]]'', being more of a haunting laugh than before. Although most species of Boo will cover their faces and become intangible when looked at, they will often sneak behind their victim and strike when their back is turned. Due to their ghostly abilities, Boos are generally invulnerable and cannot be harmed by ordinary means of attack. Despite this, they are not invincible and are especially vulnerable to the light. If they are exposed to a source of light, Boos are usually weakened, and in some cases, they may even be defeated. Usually, they can also have other weaknesses. Because of their intolerance to the light, Boos will often hide if they are trapped in lit rooms. However, King Boo claims that Boos cannot truly be killed. While the ghosts generally appear to be more afraid of their victims than their victim is of them, this is not always the case. Some Boos have absolutely no problem meeting their victim's gaze, and will even try to attack. Boos tend to have a taste for the fine arts, as seen in ''[[Paper Mario]]'' and ''[[Mario Party 4]]''. In ''[[Luigi's Mansion: Dark Moon]]'' it is shown that Boos will actually save someone if only later to trick them. This is seen when Luigi watches through pipe in the [[Old Clockworks]] as a Yellow Toad balances on a ledge. Some Boos appear and watch the Toad before it falls off the ledge, which is later found to be quite a drop, the Boos show a large amount of concern and shock when this happens before diving down for the Toad. The Toad is later found in a painting because of the Boos.

Boos are often characterized by their sub-species despite their similarities in appearance and attack manner. Boo species tend to vary wildly in size, with some such as [[Boo Buddy|Boo Buddies]] being miniature, while others such as the [[Big Boo]]s boast gigantic size. 

In ''[[Luigi's Mansion]]'', [[Professor E. Gadd]] notes that Boos have mysterious powers that increase when they gather together in large groups. While it is difficult to stop them, they can be weakened if one is able to defeat members of the group. Although in ''Luigi's Mansion: Dark Moon'' this does not seem to affect them or King Boo in any way suggesting that they do not always need to be in groups anymore.

Boos have few predators, their only known threat being a [[Spike]] named [[Tubba Blubba]] in ''Paper Mario'', when he began devouring Boos. This, however, may have been his revenge for the countless times the ghosts scared him.
====Color variations====
Boos come in many different colors. The following is a list of all known Boos and the first appearance of the respective Boo.
{|class="wikitable"style="text-align:center;width:80%"
|-
!width="10%"|Image
!width="30%"|Color
!width="30%"|First appearance
|-
|[[File:MPA Boo.png]]
|White
|''[[Super Mario Bros. 3]]''
|-
|[[File:MPA Boo blue.png]]
|Blue
|''[[Super Mario World]]'' (as [[Big Boo]]s)
|-
|[[File:MPA Boo red.png]]
|[[Red Boo|Red]]
|''[[Super Mario Bros. Deluxe]]'' 
|-
|[[File:SMBDX Green Boo.png]]
|Green
|''Super Mario Bros. Deluxe''
|-
|[[File:BlackBoo.png]]
|Black
|''Super Mario Bros. Deluxe'' 
|-
|[[File:Bootler.png|50px]]
|Chartreuse
|''[[Paper Mario]]'' 
|-
|[[File:Lady Bow PM2.png|60px]]
|Mint
|''Paper Mario'' 
|-
|[[File:Herbert.png]]
|Brown
|''Paper Mario'' 
|-
|[[File:Lahla.png|65px]]
|Light-blue
|''[[Paper Mario: The Thousand-Year Door]]'' 
|-
|
|Yellow
|''[[Mario Party DS]]''
|}

===Tools===
*[[Boo's Sheet]] - ''[[Paper Mario: The Thousand-Year Door]]
*[[Fright Bomb]] - ''[[Super Mario RPG: Legend of the Seven Stars]]
*[[Boo Bell]] - ''[[Mario Party 2]]
*[[Boo's Crystal Ball]] - ''[[Mario Party 4]]
*[[Boo Biscuit]] - ''[[Mario & Luigi: Dream Team]]

===Habitat===
Boos typically make their homes in dark forests, such as [[Forever Forest]] and the [[Boo Woods]], and tend to be most commonly found in older buildings such as mansions, castles, and [[Ghost House]]s. Although most of them live in such dwellings, they also seem to enjoy wastelands. One of the only known Boo villages lies in [[Gusty Gulch]].
 
They are typically found in groups because their fears make them find strength in big numbers.

===Allegiance===
Though most Boos tend to side with Bowser and [[King Boo]], they seem to, for the most part, actually stand as neutral. For example, Boos are by now a common enemy in most side-scrolling games; however, in the ''Paper Mario'' series and now increasingly in the multiplayer games, Boos have been seen to take the side of the [[Mushroom Kingdom]]. Lady Bow, in fact, helped [[Mario]] save the kingdom in ''[[Paper Mario]]''. In another example, the Boos in the [[Creepy Steeple]] from ''[[Paper Mario: The Thousand-Year Door]]'' attack Mario initially, but later in the game Mario is sent a friendly letter from one of them. King Boo, on the other hand, has several times been shown to wish nothing but terrible things for the heroes, but especially [[Luigi]] (although this could be accredited to Luigi being easily scared, making him a prime target for most Boo antics). They also have attacked [[Bowser]] in some games, such as the [[Mario Party (series)|''Mario Party'' series]], mainly from ''[[Mario Party 5]]'' to ''[[Mario Party 8]]''.

===Language===
As hinted in the game ''[[Super Mario Galaxy]]'', Boos have their own unique language called Booish. It most probably is spoken only by Boos since Mario cannot understand it. However, upon absorbing a [[Boo Mushroom]] and turning into [[Boo Mario]], he gains the ability to read it, if not speak it as well.

''[[Paper Mario]]'' also features Boos replacing certain words with "Boo", possibly as a part of the Booish language:
<blockquote>
''I am so bored!! Boo-ored!

''Boo-st of luck!

''Hey, what can I Boo for you?

''It's going to be the most Boo-tiful wedding ever!
</blockquote>

==Profiles and statistics==
{{main|List of Boo profiles and statistics}}
===''[[Mario & Luigi: Superstar Saga]]''===
{{:Mario & Luigi: Superstar Saga bestiary|transcludesection=Boo|align=horizontal|image=[[File:MLSS Boo Idle.gif]]}}

===''[[Paper Mario: Color Splash]]''===
{{:Paper Mario: Color Splash bestiary|transcludesection=Boo|align=horizontal|image=[[File:PMCS Boo Idle Animated.gif]]}}

===''Super Mario RPG'' (Nintendo Switch)===
{{:Super Mario RPG (Nintendo Switch) bestiary|transcludesection=Boo}}

==Gallery==
{{main-gallery}}
<gallery>
SMW Art - Boo Buddies.png|''[[Super Mario World]]''
MP2 Boo Artwork.png|''[[Mario Party 2]]''
BooTennis64.png|''[[Mario Tennis (Nintendo 64)]]''
MPA Boo Artwork.jpg|''[[Mario Party Advance]]''
Boo Artwork - Mario Party Island Tour.png|''[[Mario Party: Island Tour]]''
Boo Artwork - Mario Golf World Tour.png|''[[Mario Golf: World Tour]]''
</gallery>

==Audio samples==
{{media table
|file1=Boo Laugh 1.oga
|title1=''[[Super Mario 64]]''
|description1=A Boo's laugh
|file2=Ghost-005.oga
|title2=''[[Luigi's Mansion]]''
|description2=A Boo's laugh
|file3=Boo Laugh 2.oga
|title3=''[[New Super Mario Bros.]]''
|description3=A Boo's laugh
|file4=Boo Laugh 3.oga
|title4=''[[New Super Mario Bros.]]''
|description4=A Boo's laugh
|file5=Super Mario Galaxy Boo laugh.oga
|title5=''[[Super Mario Galaxy]]''
|description5=A Boo's laugh
}}

==Names in other languages==
{{foreign names
|Jpn=テレサ
|JpnC=<ref>{{cite|author=Shogakukan editors|date=2006|title=「敵キャラクターリスト」in『ニュー・スーパーマリオブラザーズ: 任天堂公式ガイドブック』|url=i.imgur.com/rilbHbm.jpg|language=ja|location=Tokyo|publisher=Shogakukan|isbn=4-091063-07-1|page=18}}</ref><ref> [[:File:Card 37.jpg|''Super Mario RPG'' trading card]] </ref>
|JpnR=Teresa
|JpnM=From「{{ruby|照|て}}れ{{ruby|屋|や}}」(''tere-ya'', a very shy person) and possibly「~さ」(''-sa'', a nominalizing suffix meaning "-ness") Romanized in ''Super Mario World'' as "''Telesa''".
|Jpn2=テレサ（{{ruby|小|しょう}}）
|Jpn2N=''Yoshi's Island DS''
|Jpn2R=Teresa (Shō)
|Jpn2M="Boo (Small)", in comparison to [[Big Boo]]
|Jpn2C=<ref>{{cite|quote=「テレサ（{{ruby|大|だい}}・{{ruby|小|しょう}}）」|date=April 11, 2007|title=「ヨッシーアイランドDS任天堂公式ガイドブック」 (''Yoshi's Island DS Nintendo Kōshiki Guidebook'')|publisher=Shogakukan|language=ja|isbn=978-4-09-106361-8|page={{file link|YIDS Shogakukan P22.jpg|22}}}}</ref>
|ChiS=害羞幽灵
|ChiSR=Hàixiū Yōulíng
|ChiSM=Shy Ghost
|ChiS2=嘘嘘鬼
|ChiS2N=prior to ''Mario Tennis Aces''
|ChiS2R=Xūxū Guǐ
|ChiS2M=From「嘘」(''xū'', "boo") and「鬼」(''guǐ'', "ghost")
|ChiS2C=<ref>{{cite|author=无敌阿尔宙斯|date=August 28, 2013|deadlink=y|archive=web.archive.org/web/20170227153847/http://tieba.baidu.com/p/2560204606|title=神游 超级马力欧世界 敌人官译|publisher=Baidu Tieba|language=zh-hans|accessdate=July 27, 2024}}</ref>
|ChiS3=淘气鬼
|ChiS3R=Táoqìguǐ
|ChiS3M=Scallywag
|ChiS3C=<ref>{{file link|Mario Happy Meal 2016 CN Promotional Image.jpg|McDonald's China, Winter 2016 Happy Meal promotion}}</ref>
|ChiT=害羞幽靈
|ChiTR=Hàixiū Yōulíng
|ChiTM=Shy Ghost
|ChiT2=幽靈
|ChiT2N=[[LINE#Talking Super Mario Animated Stickers|Talking ''Super Mario'' Animated Stickers]]
|ChiT2R=Yōulíng
|ChiT2M=Ghost
|ChiT2C=<ref>{{cite|url=store.line.me/stickershop/product/5835/zh-Hant|language=zh-hant|title=超級瑪利歐兄弟有聲動態貼圖 – LINE貼圖 {{!}} LINE STORE|publisher=LINE STORE|accessdate=July 3, 2021}}</ref>
|Dut=Boo
|DutC=<ref name=spirit>{{cite|author=[[Spirit (Super Smash Bros. Ultimate)|Spirit]] inventory|title=''[[Super Smash Bros. Ultimate]]'' by [[Nintendo]], [[Sora Ltd.]], and [[Bandai Namco Holdings|BANDAI NAMCO Studios Inc]]|publisher=Nintendo|date=7 Dec. 2018}}</ref>
|Fre=Boo
|FreC=<ref name=spirit/>
|Fre2=Fantôme
|Fre2M=Ghost
|Fre3=Les amis de Boo
|Fre3N=''Super Mario World'' instruction booklet
|Fre3M=Boo's friends
|Fre4=Boo Buddy
|Fre4N=''Hotel Mario''
|Fre4C=<ref>{{cite|url=www.oldiesrising.com/noticespdfV2/Philips%20CDi/Hotel%20Mario.pdf|title=French ''Hotel Mario'' instruction booklet|format=PDF|page=9}}</ref>
|Ger=Buu Huu
|GerM=Boo Hoo
|GerC=<ref>{{cite|author=Nintendo of Europe GmbH|title=''Super Mario Bros. 3 Spielanleitung''|language=de|location=Großostheim|publisher=Nintendo of Europe GmbH|date=1991|page=38}}</ref><ref name=spirit/>
|Ger2=Buu-Baby<ref>{{cite|author=Menold, Marcus, Claude M. Moyse, and Andreas G. Kämmerer, editors|date=1993|title=''Der offizielle Nintendo Spieleberater "Super Mario World"''|location=Großostheim|publisher=[[Nintendo|Nintendo of Europe GmbH]]|language=de|page=19}}</ref>
|Ger2M=Boo Baby
|Ger2N=''Super Mario World''
|Ita=Boo
|ItaC=<ref>{{cite|title=''Super Mario Bros. 3'' Italian instruction booklet|url=www.mariocastle.it/risorse/manuali/super-mario-bros-3/39.jpg|format=JPG|publisher=Nintendo|language=it|page=38}}</ref><ref name=spirit/>
|Ita2="Boo" Diddly
|Ita3=Boo Hoo
|Ita3N=''Mario Kart DS''
|Ita4=Fischio
|Ita4M=Whistle; literal translation from "to boo"
|Ita4C=<ref>{{cite|title=[[List of New Super Mario Bros. Wii trading cards|''New Super Mario Bros. Wii'' - Album ufficiale]]|page=6}}</ref>
|Kor=부끄부끄
|KorR=Bukkeu-bukkeu
|KorM=Partial repetition of 부끄럽다 (''bukkeureopda'', to be shy)
|KorN=
|Kor2=테레사
|Kor2R=Telesa
|Kor2M=Same as Japanese name
|Kor2N=''Mario Party 5'' instruction booklet
|Kor2C=<ref>Scanlines16.com (May 3, 2012). [http://scanlines16.com/en/blog-3/retro-gaming/game-cube/gamecube-korean-master-list/ Gamecube : Korean Master-List !] Retrieved November 18, 2024.</ref>
|Por=Bu
|PorM=Boo
|PorC=<ref>Detona (October 17, 2024). [https://www.youtube.com/watch?v=G-b0z0pRq4o Super Mario Party Jamboree - Jornada das Tarefas - Completo 100%]. ''Youtube'' (Brazilian Portuguese). Retrieved October 23, 2024.</ref><ref>{{cite|url=www.lego.com/pt-pt/product/character-packs-series-3-71394|title=Packs de Personagens – Série 3|publisher=LEGO.com|language=pt-pt|accessdate=March 30, 2025|archive=web.archive.org/web/20250330172705/https://www.lego.com/pt-pt/product/character-packs-series-3-71394}}</ref>
|Por2=Monstro
|Por2N=''The Adventures of Super Mario Bros. 3''
|Por2M=Monster
|Por2C=<ref>[https://www.youtube.com/watch?v=uLmERqyWbF4&list=PLwzf4mOPE8Bmhgll2-ndwQWhRpiCUMR6G&index=7 Super Mario Bros. 3 - Tempestade no Reino (Dublagem Herbert Richers)]</ref>
|Rom=Bau Bau
|RomN=''The Adventures of Super Mario Bros. 3''
|RomM=Boogeyman
|RomC=<ref>{{cite|date=May 20, 2015|url=ok.ru/videoembed/26892634756|title="Reign Storm", dubbed in Romanian by KidsCo|publisher=Odnoklassniki (OK.ru)|language=ro|accessdate=May 24, 2024}}</ref>
|Rom2=Fantomă
|Rom2N=''Super Mario World'' television series
|Rom2M=Ghost
|Rom2C=<ref>May 20, 2015. [http://ok.ru/videoembed/26859866756 "Ghosts 'R' Us", dubbed in Romanian by KidsCo]. ''Odnoklassniki (OK.ru).'' Retrieved January 4, 2016.</ref>
|Rom3=Boo
|Rom3C=<ref>{{file link|McDonaldsRomania2016Banner.jpg|McDonald's Romania, Summer 2016 Happy Meal promotion}}</ref>
|Rus=Бу
|RusR=Bu
|RusM=Boo
|Rus2=Привидение
|Rus2N=prior to ''Luigi's Mansion: Dark Moon'' + its official website
|Rus2R=Prividenie
|Rus2M=Ghost
|SpaA=Boo
|SpaAC=<ref name=spirit/>
|SpaA2=Bú
|SpaA2N=2010-2017
|SpaA2M=Boo
|SpaE=Boo
}}

==References==
<references/>

==External links==
{{NIWA|SmashWiki=1|Ukikipedia=1|ZeldaWiki=1}}
===StrategyWiki===
*[[strategywiki:Super_Mario_Bros._3/Enemies|Boo § ''Super Mario Bros. 3'']]
*[[strategywiki:Super_Mario_World/Enemies#"Boo"_Buddy|Boo "Buddy" § ''Super Mario World'']]
*[[strategywiki:Super_Mario_64/Enemies#Boo|Boo § ''Super Mario 64'']]
*[[strategywiki:Super_Mario_Sunshine/Enemies#Boo|Boo § ''Super Mario Sunshine'']]
*[[strategywiki:New Super Mario Bros./Enemies|Boo § ''New Super Mario Bros.'']]
*[[strategywiki:Super_Mario_Galaxy/Enemies#Boo|Boo § ''Super Mario Galaxy'']]
*[[strategywiki:New Super Mario Bros. Wii/Enemies#Ghosts|Boo § ''New Super Mario Bros. Wii'']]
*[[strategywiki:Super_Mario_Galaxy_2/Enemies#Boo|Boo § ''Super Mario Galaxy 2'']]
*[[strategywiki:New_Super_Mario_Bros._2/Enemies#Boos|Boo § ''New Super Mario Bros. 2'']]
*[[strategywiki:Mario_Kart_Super_Circuit/Items#Boo|Boo § ''Mario Kart: Super Circuit'']]
*[[strategywiki:Mario_Kart_DS/Items#Boo|Boo § ''Mario Kart DS'']]
*[[strategywiki:Paper Mario: The Thousand-Year Door/Enemies|Boo § ''Paper Mario: The Thousand-Year Door'']]
*[[strategywiki:Super Paper Mario/Enemies|Boo § ''Super Paper Mario'']]

===Other wikis===
*[https://zeldadungeon.net/wiki/Boo_Buddy Boo Buddy on Zelda Dungeon Wiki]
*[https://triforcewiki.com/wiki/Boo Boo on Triforce Wiki]

{{navboxes|
{{Boos}}
{{SMB3}}
{{TAOSMB3}}
{{SMW}}
{{SMW TV}}
{{NAB}}
{{SMK}}
{{SML2}}
{{MB}}
{{Yoshi's Safari}}
{{HM}}
{{YI}}
{{Mario Clash}}
{{SMRPG}}
{{SM64}}
{{MK64}}
{{EBBMB}}
{{MP}}
{{SMB}}
{{MP2}}
{{MT N64}}
{{MT GBC}}
{{PM}}
{{MP3}}
{{MKSC}}
{{LM}}
{{Super Mario Sunshine}}
{{MP4}}
{{MGTT}}
{{MKDD}}
{{MP5}}
{{M&LSS}}
{{MGAT}}
{{MVDK}}
{{PMTTYD}}
{{MPL}}
{{MPT}}
{{MP6}}
{{YTT}}
{{MPA}}
{{DDRMM}}
{{MSB}}
{{MKAGP}}
{{SPP}}
{{MP7}}
{{MKDS}}
{{M&LPIT}}
{{NSMB}}
{{MH3O3}}
{{YIDS}}
{{MKAGP2}}
{{SPM}}
{{MSC}}
{{MP8}}
{{SMG}}
{{M&SATOG}}
{{Mario Kart Wii}}
{{Mario Super Sluggers}}
{{M&SATOWG}}
{{NSMBW}}
{{SMG2}}
{{MSM}}
{{SM3DL}}
{{M&SATLOG}}
{{MK7}}
{{MP9}}
{{MTO}}
{{NSMB2}}
{{PMSS}}
{{NSMBU}}
{{LMDM}}
{{MKAGPDX}}
{{SM3DW}}
{{MPIT}}
{{YNI}}
{{MK8}}
{{CTTT}}
{{MP10}}
{{P&DSMBE}}
{{SMM}}
{{MTUS}}
{{M&LPJ}}
{{MM&FaC}}
{{M&SATROG}}
{{PMCS}}
{{MPSR}}
{{SMR}}
{{Mario Sports Superstars}}
{{M+RKB}}
{{MPTT100}}
{{MTA}}
{{SMP}}
{{SMM2}}
{{MKT}}
{{DMW}}
{{PMTOK}}
{{MKLHC}}
{{MGSR}}
{{MPS}}
{{SMBW}}
{{SMPJ}}
{{M&LB}}
{{Mario Kart World}}}}
[[Category:Boos|*]]
[[Category:Playable characters]]
[[Category:Racers]]
[[Category:Shopkeepers]]
[[Category:Thieves]]
[[Category:Bowser Jr.'s Journey allies]]
[[Category:Captain Toad: Treasure Tracker enemies]]
[[Category:Dance Dance Revolution: Mario Mix enemies]]
[[Category:Dinosaur Dilemma enemies]]
[[Category:Dr. Mario World]]
[[Category:Excitebike: Bun Bun Mario Battle objects]]
[[Category:Hotel Mario enemies]]
[[Category:LEGO Super Mario characters]]
[[Category:Luigi's Mansion ghosts]]
[[Category:Luigi's Mansion: Dark Moon ghosts]]
[[Category:Luigi's Mansion 3 ghosts]]
[[Category:Mario + Rabbids Kingdom Battle enemies]]
[[Category:Mario & Luigi: Paper Jam enemies]]
[[Category:Mario & Luigi: Partners in Time enemies]]
[[Category:Mario & Luigi: Superstar Saga enemies]]
[[Category:Mario & Sonic at the London 2012 Olympic Games species]]
[[Category:Mario & Sonic at the Olympic Games species]]
[[Category:Mario & Sonic at the Olympic Winter Games]]
[[Category:Mario & Sonic at the Rio 2016 Olympic Games characters]]
[[Category:Mario Bros. enemies]]
[[Category:Mario Clash enemies]]
[[Category:Mario Golf (Nintendo 64)]]
[[Category:Mario Golf: Advance Tour characters]]
[[Category:Mario Golf: Super Rush characters]]
[[Category:Mario Golf: Toadstool Tour characters]]
[[Category:Mario Golf: World Tour characters]]
[[Category:Mario Hoops 3-on-3 playable characters]]
[[Category:Mario Kart 8 species]]
[[Category:Mario Kart 8 Deluxe]]
[[Category:Mario Kart 64 items]]
[[Category:Mario Kart 64 species]]
[[Category:Mario Kart Arcade GP items]]
[[Category:Mario Kart Arcade GP 2 items]]
[[Category:Mario Kart Arcade GP DX items]]
[[Category:Mario Kart DS items]]
[[Category:Mario Kart DS species]]
[[Category:Mario Kart: Double Dash!! species]]
[[Category:Mario Kart: Super Circuit items]]
[[Category:Mario Kart: Super Circuit species]]
[[Category:Mario Kart Tour species]]
[[Category:Mario Kart Wii species]]
[[Category:Mario Kart World items]]
[[Category:Mario Party characters]]
[[Category:Mario Party 2 characters]]
[[Category:Mario Party 3 characters]]
[[Category:Mario Party 4 species]]
[[Category:Mario Party 5 characters]]
[[Category:Mario Party 6 characters]]
[[Category:Mario Party 7 characters]]
[[Category:Mario Party 8 characters]]
[[Category:Mario Party 9 characters]]
[[Category:Mario Party 10 characters]]
[[Category:Mario Party Advance characters]]
[[Category:Mario Party Advance enemies]]
[[Category:Mario Party Advance species]]
[[Category:Mario Party DS characters]]
[[Category:Mario Party-e]]
[[Category:Mario Party: Island Tour characters]]
[[Category:Mario Party: Star Rush characters]]
[[Category:Mario Party: The Top 100 characters]]
[[Category:Mario Pinball Land enemies]]
[[Category:Mario Power Tennis characters]]
[[Category:Mario Sports Mix species]]
[[Category:Mario Sports Superstars characters]]
[[Category:Mario Strikers Charged species]]
[[Category:Mario Super Sluggers playable characters]]
[[Category:Mario Superstar Baseball characters]]
[[Category:Mario Tennis (Nintendo 64) characters]]
[[Category:Mario Tennis Aces characters]]
[[Category:Mario Tennis (Game Boy Color) characters]]
[[Category:Mario Tennis Open characters]]
[[Category:Mario Tennis: Ultra Smash characters]]
[[Category:Mario's Picross]]
[[Category:Mario vs. Donkey Kong enemies]]
[[Category:Mini Mario & Friends: amiibo Challenge enemies]]
[[Category:Minion Quest: The Search for Bowser allies]]
[[Category:New Super Luigi U enemies]]
[[Category:New Super Mario Bros. enemies]]
[[Category:New Super Mario Bros. 2 enemies]]
[[Category:New Super Mario Bros. U enemies]]
[[Category:New Super Mario Bros. Wii enemies]]
[[Category:New Super Mario Bros. Wii trading cards]]
[[Category:Paper Mario species]]
[[Category:Paper Mario: Color Splash enemies]]
[[Category:Paper Mario: Sticker Star enemies]]
[[Category:Paper Mario: The Origami King enemies]]
[[Category:Paper Mario: The Thousand-Year Door enemies]]
[[Category:Paper Mario: The Thousand-Year Door species]]
[[Category:Puzzle & Dragons: Super Mario Bros. Edition bosses]]
[[Category:Puzzle & Dragons: Super Mario Bros. Edition enemies]]
[[Category:Super Mario 3D Land enemies]]
[[Category:Super Mario 3D World enemies]]
[[Category:Super Mario 64 enemies]]
[[Category:Super Mario Advance 4: Super Mario Bros. 3 enemies]]
[[Category:Super Mario amiibo line]]
[[Category:Super Mario Bros. 3 enemies]]
[[Category:Super Mario Bros. Deluxe]]
[[Category:Super Mario Bros. Wonder enemies]]
[[Category:Super Mario Galaxy enemies]]
[[Category:Super Mario Galaxy species]]
[[Category:Super Mario Galaxy 2 enemies]]
[[Category:Super Mario Kart items]]
[[Category:Super Mario Kart species]]
[[Category:Super Mario Land 2: 6 Golden Coins enemies]]
[[Category:Super Mario Maker enemies]]
[[Category:Super Mario Maker 2 enemies]]
[[Category:Super Mario Party characters]]
[[Category:Super Mario Party Jamboree characters]]
[[Category:Super Mario RPG: Legend of the Seven Stars enemies]]
[[Category:Super Mario Run enemies]]
[[Category:Super Mario Sunshine enemies]]
[[Category:Super Mario World enemies]]
[[Category:Super Mario World (television series)]]
[[Category:Super Mario World 2: Yoshi's Island enemies]]
[[Category:Super Paper Mario enemies]]
[[Category:Super Princess Peach enemies]]
[[Category:Super Smash Bros. Brawl stickers]]
[[Category:Super Smash Bros. Brawl trophies]]
[[Category:Super Smash Bros. for Nintendo 3DS trophies]]
[[Category:Super Smash Bros. for Wii U trophies]]
[[Category:Super Smash Bros. Melee trophies]]
[[Category:Super Smash Bros. Ultimate spirits]]
[[Category:The Adventures of Super Mario Bros. 3 enemies]]
[[Category:Yakuman DS]]
[[Category:Yoshi (game)]]
[[Category:Yoshi Topsy-Turvy enemies]]
[[Category:Yoshi's Island DS enemies]]
[[Category:Yoshi's Island: Super Mario Advance 3]]
[[Category:Yoshi's New Island enemies]]
[[Category:Yoshi's Safari enemies]]
[[Category:Yoshi's Story enemies]]
[[de:Buu Huu]]
[[it:Boo]]