Editing 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]]}}

|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=''[[Nintendo World Championships: NES Edition]]'' ([[List of games by date#2024|2024]])

|latest_portrayal=[[Sanae Suzaki]] ([[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>[[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|title=''Super Mario Bros. 3'' instruction booklet|page=38|date=1990|publisher=Nintendo of America|language=en-us}}</ref> a nod to American R&B singer {{iw|wikipedia|Bo Diddley}}, and later '''Boo Buddies'''<ref>{{cite|title=''Super Mario World'' instruction booklet|page=24|date=1991|language=en-us|publisher=Nintendo of America}}</ref><ref>{{cite|title=''Yoshi'' (NES) instruction booklet|page=5 and 12|publisher=Nintendo of America|date=1991|language=en-us}}</ref><ref>{{cite|title=''Yoshi'' (Game Boy) instruction booklet|page=4 and 11|publisher=Nintendo of America|date=1991|language=en-us}}</ref><ref>{{cite|author=Miller, Kent and Terry Munson|title=''Super Mario World 2: Yoshi's Island'' Player's Guide|language=American English|date=1995|publisher=Nintendo of America|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|title=''Super Mario Advance 4: Super Mario Bros. 3'' Prima's Official Strategy Guide|page=19, 35, 45, 56, 57, 66, 71, 82, 85, 97, 102, 103, 104, 121, 122, 125, and 126|publisher=[[Prima Games]]|date=October 21, 2003|language=en-us|isbn=0-7615-4425-9}}</ref> or simply '''Ghosts'''<ref>{{cite|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|quote=The candle in this contraption scares Ghosts into covering their eyes, so you can safely walk your Mini right through them.}}</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 [[wikirby:Mumbies|Mumbies]] in the ''[[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|language=en|publisher=The Guardian|accessdate=May 24, 2024}}</ref><ref>{{cite|url=archive.org/stream/Nintendo_Power_Issue001-Issue127/Nintendo%20Power%20Issue%20080%20January%201996#page/n26/mode/1up|date=January 1996|page=25|title=''Nintendo Power'' Volume 80|publisher=Nintendo of America|language=en-us|author=Tilden, Gail, et al.}}</ref>

====''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|title=''Super Mario Bros. 3'' instruction booklet|page=38|date=1990|publisher=Nintendo of America|language=en-us}}</ref> appear in ''[[Super Mario Bros. 3]]''. They are first encountered in {{world-link|2|fort|World 2-Fortress}}. 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 have a variant, [[Stretch]]es "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.

====''Super Mario World'' / ''Super Mario World: Super Mario Advance 2''====

[[File:SMWBoo.png|frame]]

"Boo" Buddies (called "Boo" Diddlys earlier in development<ref>{{cite|title=[[tcrf:Prerelease:Super Mario World (SNES)/Background Graphics and Tilemaps#Enemy Cast List|Prerelease:''Super Mario World'' (SNES)/Background Graphics and Tilemaps § Enemy Cast List]]|publisher=The Cutting Room Floor|accessdate=August 6, 2020}}</ref> appear in ''[[Super Mario World]]'' and [[Super Mario World: Super Mario Advance 2|its reissue]]. They are 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 change their face very briefly if looked at for long enough. "Boo" Buddies appear to have multiple tails. 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]]. 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 ''[[Super Mario Land 2: 6 Golden Coins]]''. Compared to other games, they move in a slower, wave-like pattern toward Mario. Boo Buddies in this game are found in the [[Pumpkin Zone]]. A thrown [[Green Shell]] can defeat it. A variant named [[Ghost Goomba]]s also appears in this game.

[[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|publisher=[[Prima Games]]|isbn=0-7615-2103-8|title=''Nintendo 64 Game Secrets, 1999 Edition'' Prima's Official Strategy Guide|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|author=Boo|language=en|quote=You...can't...EAT...ghosts! Eee hee hee!|title=''Super Mario 64 DS''|date=2004|publisher=Nintendo}}</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|author=Boo|quote=Ghosts...don't...DIE! Heh, heh, heh! Can you get out of here...alive?|location=Big Boo's Haunt|date=1996|publisher=Nintendo|language=en|title=''Super Mario 64''}}</ref> A Boo appears in the hallway of the Mushroom Castle after twelve Stars are collected, or eight in the remake. By selecting the [[Eye to Eye in the Secret Room|sixth mission]] of Big Boo's Haunt in the remake directly, a Boo wearing a [[Luigi Cap|Luigi's cap]] appears in the stage.

{{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|language=en-us|title=''Super Mario Bros. Deluxe'' instruction booklet|page=20|publisher=Nintendo of America|date=1999}}</ref> with a yellow outline. The Black Boo travels in a way mimicking the player's best time.

[[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.|language=ja|publisher=[[Shogakukan]]|location=Tokyo|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'')|page=107|isbn=978-4-09-106569-8}}</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.

[[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]]''. They are encountered in the [[Ghostly Galaxy]], the [[Bigmouth Galaxy]] (in underwater areas), the [[Deep Dark Galaxy]], and the [[Sand Spiral Galaxy]] only. Boos become transparent when the player character looks at them, but are opaque and go after the player character if they are not looking. 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. A large Boo in Deep Dark Galaxy has a [[Power Star]] in it during the secret mission. Varieties that appear include [[Big Boo|Atomic Boo]] and the debuting [[Bomb Boo]]s, and there is a 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.

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]].

Boos appear in ''[[Super Mario Galaxy 2]]''. They behave identically as in ''Super Mario Galaxy''. They are encountered in [[Haunty Halls Galaxy]], [[Boo Moon Galaxy]], [[Battle Belt Galaxy]], and [[Slimy Spring Galaxy]], the latter two having the underwater type. 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.

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.

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.

 

[[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.

 

 

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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.

[[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 von Koopa|Kooky]].

[[File:SMWTV Yoshi and Boo.jpg|thumb|left|Yoshi encountering a Boo 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.

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.

===''Yoshi''===

Boo Buddies are objects in ''[[Yoshi (game)|Yoshi]]''. They are one of six types of objects to fall on the play field. Boo Buddies are depicted similarly as in ''[[Super Mario World]]''.

|[[File:SMK Boo Item Box Sprite 1.png]]<br>[[File:SMK Boo Item Box Sprite 2.png]]

'''Ghosts'''<ref>{{cite|date=1992|publisher=Nintendo of America|title=''Super Mario Kart'' instruction booklet|page=14|language=en}}</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.

Boos (named '''Ghost Bonuses''' on one occasion<ref>{{cite|title=''Nintendo Magazine System'' (AU) Issue 49|date=April 1997|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.

[[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|isbn=0-7440-0091-2|title=''Mario Kart: Super Circuit'' Official Racing Guide|publisher=BradyGames|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.

Boos, named '''Boo Hoo''' in British English,<ref>{{cite|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|date=2005|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.

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.

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.

[[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|title=Mario Kart 8 Deluxe Tips - Boo Item Analysis|url=youtu.be/OUdaqb7Cj2I|publisher=YouTube|accessdate=May 9, 2017}}</ref>

====''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)]].

 

Boos are obstacles in the course [[Boo Fortress]] in ''[[Mario Kart Live: Home Circuit]]''. They frighten any player who hits them.

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.

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.

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''===

Boos<ref>{{cite|title=''Yoshi no Road Hunting'' instruction booklet|language=ja|date=1993|publisher=Nintendo|page=21}}</ref> (misnamed "Big Boo" in the English manual<ref>{{cite|title=''Yoshi's Safari'' instruction booklet|page=20|language=en-us|publisher=Nintendo of America|date=1993}}</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.

 

===''Mario Bros.'' series===

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.

 

[[File:Big Boo Artwork - Mario Clash.png|thumb|Artwork from ''Mario Clash'']]

Boos<ref>{{cite|title=マリオクラッシュ (''Mario Kurasshu'') instruction booklet|page=20|date=1995|publisher=Nintendo|language=ja}}</ref> (misnamed "Big Boo" in the English manual<ref name=ClashBoo>{{cite|title=''Mario Clash'' instruction booklet|page=21|date=1995|publisher=Nintendo of America|language=en-us}}</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/>

[[File:HM Boo.png|thumb|left|A Boo from ''Hotel Mario'']]

'''Boo Buddies'''<ref>{{cite|title=''Hotel Mario'' instruction book|page=16|date=1994}}</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.

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.

[[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]]. In the original game, the English translation erroneously calls them "The Big Boo", whereas the remake simply calls them Boos. In the Japanese version, they are, in fact, referred to as Teresa as they are in other games. 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]]s. 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|title=''Super Mario RPG: Legend of the Seven Stars'' instruction booklet|date=1996|language=en|publisher=Nintendo of America|page=41}}</ref> One Boo lives in [[Monstro Town]] as part of the [[Three Musty Fears]].

 

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.

The normal Boo<ref>{{cite|language=ja|publisher=Shogakukan|date=February 20, 1998|isbn=4-09-102619-2||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'')|page={{file link|Yoshi Story Shogakukan P7.jpg|7}}}}</ref> is mistakenly called a Big Boo<ref>{{cite|author=Leung, Jason, Terry Munson, and Scott Pelland|title=''Yoshi's Story'' Player's Guide|publisher=Nintendo Power|page=10|date=1998|language=en-us}}</ref> in the ''[[Nintendo Power]]'' guide.

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.

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.

[[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]].

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.

[[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.

[[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 Folley]]. 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.

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]].

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.

[[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|author=Boo|date=2005|quote=That's right! We three Boos are best--|title=''Mario Party Advance''|publisher=Nintendo|language=en}}</ref><ref>{{cite|author=Boo|date=2005|quote=When did we pick up a fourth?|publisher=Nintendo|title=''Mario Party Advance''|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.

Boo is a playable character in ''[[Mario Party 7]]''. He 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.

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

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.

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.

[[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.

[[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]].

[[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.

 

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]]''.

 

 

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.

 

In ''[[Super Mario Party Jamboree]]'', 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|publisher=YouTube|language=en|timestamp=07:46|accessdate=September 9, 2024}}</ref>

{{MGTT character infobox

|title=Boo

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]].

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.

[[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''====

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]].

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.

|image1=PM Boo Sprite.png

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 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.

[[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 return as enemies in ''[[Super Paper Mario]]''. In this game, they turn invisible if Mario looks at them, but they turn visible and chase him if he is not looking at them, similar to their behavior in ''Super Mario 64''. To defeat them, the player must approach them from the back and then attack them. Additionally, the [[Flipside Arcade]] houses a Boo themed shooting game, Mansion Patrol. This game has the player shooting Boos, including Dark Boos and occasionally Atomic Boos, to score points. A [[Toad]] frequently appears to give power-ups, as long as the player saves him from his Boo captor. Lady Bow also makes three cameos in this game.

[[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.

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.

 

[[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]].

[[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.

Boos are enemies in ''[[Luigi's Mansion: Dark Moon]]''. 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 [[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===

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)#Boo|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 [[smashwiki:Smash Tour|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 [[smashwiki:Dark Realm|Dark Realm]]. The spirit battle takes place on the [[Mushroom Kingdom U]] stage, with an invisible grayscale [[Kirby]] as the puppet fighter.

====''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''.]]

In ''[[Mario & Luigi: Superstar Saga]]'', Boos are enemies that only appear in [[Bowser's Castle]]; they aid [[Bowletta]] along with the rest of the minions who believe her to be Bowser. Outside of battle, they hover around, attacking Mario and Luigi when they are not looking. However, they look away if Mario or Luigi make eye contact. The Boos also show the ability to teleport. In battle, a Boo has two attacks. For the first attack, the Boo will teleport in front of one of the brothers and attempt to bite him. For the second attack, it will fly up into the air and swoop into one of the Mario Bros., which can even [[Prohibited Command|prohibit the use of certain moves or items]]. The former attack can be countered with Mario or Luigi's hammer, whereas the latter can be dodged or countered by jumping. In either of these attacks, if the Boo makes a face, it will target Luigi, if it does not, it will target Mario. Boos are weak to [[Firebrand]] and [[Fire Bros. (move)|Fire Bros.]] They also have low HP, but very high defense.

[[File:MLSS Miner Boo.gif|frame|left]]

Boos wearing mining helmets and brandishing pickaxes also appear in levels 4 and 5 of [[Mysterious Mine Carts]] (levels 3 and 5 in the remake). If these Boos touch Mario, they will cause the loss of a diamond. They will slowly shrink until they disappear if the flashlight is pointed at them.

 

 

During the events of ''[[Mario & Luigi: Partners in Time]]'', Boos appear in [[Bowser's Castle]] of the past. In the field, Boos attack the same way as they did in ''Mario & Luigi: Superstar Saga''. In battle, a Boo attacks by peeking through one of its eyes; peeking with the right eye is Mario, and with the left eye, Luigi. The Boo reappears behind the corresponding bro and charges from behind; this can be avoided or countered with a jump. Boos also appear during the battle with [[Sunnycide]]. While flipped on its back, Sunnycide can summon a Boo to attack Mario or Luigi, which can be countered with a hammer. Also, when a [[Handfake]] has a [[Bowser]] sign, a Boo or a [[Fly Guy]] carries a flame from Bowser's mouth. Dark Boos are found in the [[Gritzy Caves]].

====''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]]

|[[File:BowserMemoryBoo.png]] [[File:MLBISBJJBowserMemoryBoo.png]]

Boos make a reappearance in ''[[Mario & Luigi: Bowser's Inside Story]]''. They appear in [[Bowser's Castle#Mario & Luigi: Bowser's Inside Story / Mario & Luigi: Bowser's Inside Story + Bowser Jr.'s Journey|Bowser's Castle]], where they have been brainwashed by [[Fawful]] along with the rest of Bowser's minions once he took over the castle. When Bowser gets to have a feast as a reward for beating [[Midbus]] at the [[Fawful Theater]] show, three Boos serve him food cooked by Fawful himself. However, Bowser is tricked into eating too much food and ends up getting fat, which results in him getting stuck in the floor due to his weight. Boos reappear later in the game to help many of the brainwashed minions of Bowser push the Fawful statue against him. In addition, a Boo appears whenever Bowser gets a [[level up]]. The Boo (just like the [[Fishin' Lakitu]] in Mario's or Luigi's level up screen) holds the circle for getting a bonus upgrade for the stat of the player's choice.

 

An odd thing shown in the game is a Boo and [[Koopa Troopa]] in love with each other in Bowser's Castle. They not only love each other, but also love Fawful due to the brainwashing that was put on the minions.

During the fight with [[Bowser Memory ML]], Bowser Memory L has an attack that involves a digital Boo chasing him around. The Boo can be jumped on by either Mario or Luigi to stop the attack prematurely.

Boos return in ''[[Mario & Luigi: Bowser's Inside Story + Bowser Jr.'s Journey]]'', where they additionally are found as enemies and recruitable allies in the ''Bowser Jr.'s Journey'' mode. Their special attack is Discord, which [[SPD-Down|lowers the speed]] of enemies.

Boos are referenced in ''[[Mario & Luigi: Dream Team]]''. The game features an item named [[Boo Biscuit]].

Boos appear in ''[[Mario & Luigi: Paper Jam]]'' in a minigame where the player has to save a Toad by running away from a Boo and avoiding firebars and bombs. Like in many other games, this Boo will stop if the Mario Bros. look at it, and will follow them if they look away. Boos can also be seen carrying Papercraft Boos, along with Papercraft King Boo. Their [[Paper Boo|paper versions]] also appear as regular enemies in the haunted side of [[Gloomy Woods]]. [[King Boo]] also appears as a boss in [[Gloomy Woods]]. [[Boo Biscuit]]s also return from ''[[Mario & Luigi: Dream Team]]''.

===''Mario vs. Donkey Kong'' series===

====''Mario vs. Donkey Kong''====

|[[File:MvsDK Boo.png]]<br>[[File:MvDKNSBoo.png|100px]]

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''====

|image1=MM&FaC boo on.jpg

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.

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.

[[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.

[[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.

[[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.

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.

{{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.

{{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 [[Power Sneakers|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.

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.

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.

[[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]]''. He is a starter captain-type who is billed a Technique player, giving him an advantage in accuracy or horse control, except in tennis, which bills him a Tricky type. Boo's rallies curve in tennis, making the trajectory of his shots less predictable. Boo has a default drive of 213 yards and shots that travel medium-low in a draw trajectory in golf.

 

[[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.

===Physical appearance===

[[File:Boo art04.png|thumb|left|A laughing Boo with a shy Boo]]

|(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

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.