Editing Boo

{{about|the ghost enemies that appear throughout the [[Mario (franchise)|''Mario'' franchise]]|the [[microgame]] from [[WarioWare: D.I.Y. Showcase]]|[[Boo (microgame)]]|the area in Mario Party 10|[[Boo (area)]]}}

{{Species-infobox

|expand=expandable

|image=[[File:Boo_CTTT.png|250px]]<br>A Boo from ''[[Captain Toad: Treasure Tracker]]''

|latest_appearance=''[[Super Mario 3D World + Bowser's Fury]]'' ([[List of games by date#2021|2021]])

|derived_species=[[Big & Little Boo]]<br>[[Big Boo]]<br>[[Black Boo]]<br>[[Blindfold Boo]]<br>[[Bomb Boo]]<br>[[Boo (toy)]]<br>[[Boo Balloon]]<br>[[Boo Block]]<br>[[Boo Buddies]]<br>[[Boo Buddy Snake]]<br>[[Boo Crew]]<br>[[Boo Stack]]<br>[[Bowser Memory Boo]]<br>[[Dark Boo]]<br>[[Disappearing Boo Buddy]]<br>[[Eerie]]<br>[[Fishing Boo]]<br>[[Frame Boo]]<br>[[Gold Boo]]<br>[[Green Boo]]<br>[[Hammer Knight]]<br>[[Jelly Ghost]]<br>[[Li'l Boo]]<br>[[Mad Boo]]<br>[[Mini Boo]]<br>[[Octoboo]]<br>[[Paper Boo]]<br>[[Paper Macho Boo]]<br>[[Peepa]]<br>[[Red Boo]]<br>[[Sleepy Boo]]<br>[[Stretch]]<br>[[Tail Boo]]<br>[[Terekuribō]]

|related=[[Boo Guy]]<br>[[Broozer]]

|notable=[[Big Boo (boss)]]<br>[[Boo (Mario Party 4)|Boo (''Mario Party 4'')]]<br>[[Boo (Mario Party Advance)|Boo (''Mario Party Advance'')]]<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 (boss)|Phantom]]<br>[[Stanley (Paper Mario)|Stanley]]<br>[[Spooky Speedster]]

{{quote2|Mind turning around for a minute?|Boo|[[Paper Mario: Color Splash]]}}

'''Boos''' (originally known as '''"Boo" Diddlys'''<ref>''Super Mario Bros. 3'' English instruction booklet, page 38.</ref> and later '''Boo Buddies'''<ref>''Super Mario World'' English instruction booklet, page 24.</ref><ref>''Yoshi'' instruction booklet, pages 5 and 12 on NES and pages 4 and 11 on Game Boy.</ref><ref>''Super Mario World 2: Yoshi's Island'' Nintendo Player's Guide. [[media:SMW2 Guide 126.jpg|Page 126]].</ref><ref>Hodgson, David S J. ''Super Mario Advance 4: Super Mario Bros. 3'' Prima's Official Strategy Guide. Pages 19, 35, 45, 56, 57, 66, 71, 82, 85, 97, 102, 103, 104, 121, 122, 125, 126.</ref>) are common ghost enemies in the [[Mario (franchise)|''Mario'' franchise]] 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 "arms" of some sort. However, the most distinctive characteristic of the Boos is their shy personality, where they cover their faces when someone looks directly at them. They will uncover their faces once the subject turns around.

====''Super Mario Bros. 3''====

[[File:LookinAtBoo.png|thumb|Mario encounters a Boo Diddly in [[World 8-1 (Super Mario Bros. 3)|World 8-1]]]]

[[File:SMB3Boo.jpg|thumb|left|Artwork of a Boo Diddly from ''Super Mario Bros. 3'']]

Boos first appear in ''[[Super Mario Bros. 3]]''. Here, they are referred to as “Boo” Diddlys, a pun off the late rock star {{wp|Bo Diddley}}. However, future games refer to them only as Boos. They make their first appearance in {{world-link|2|fort|World 2-Fortress}}. The Boo shields its face if [[Mario]] or [[Luigi]] look at it, but it starts to chase Mario or Luigi, faster than in succeeding games, if they look away. Boos are unable to be defeated unless the two are equipped with a [[Hammer Suit]], [[Green Shell|Koopa shell]], or [[Super Star|Starman]]. The game also has [[Stretch]]es, which are Boos with very long bodies that live in the Fortresses throughout the [[Mushroom World]]. In the original, depending on the level's palette, Boos have either a dark blue or dark red outline.

====''Super Mario World''====

In ''[[Super Mario World]]'', Boos are now called "Boo" Buddies (though they were still called "Boo" Diddly earlier in development<ref>TCRF. [[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]]. ''The Cutting Room Floor''. Retrieved August 6, 2020.</ref>) and they reside in the many [[Ghost House]]s in the game. These Boos retain their usual pattern of attack from ''Super Mario Bros. 3'' and sometimes make faces at Mario or Luigi. However, they are somewhat slower and less accurate than in ''Super Mario Bros. 3''. This game also introduces many new Boo variations, such as the [[Boo Block|Boo Buddy Block]], [[Boo Buddy Snake]], [[Boo Crew]], [[Boo Buddies|Circling Boo Buddies]], [[Eerie]]s, and [[Disappearing Boo Buddy|Disappearing Boo Buddies]]. It also introduces a giant version of the Boo, the [[Big Boo]]. One Ghost House contains a secret boss, a special [[Big Boo (boss)|Big Boo]]. The only way to defeat a Boo is with [[Super Star]]s or with [[Grab Block]]s when it is visible. Unlike later games, the Boos in this game seem to have multiple tails. The groups of Boos also have different facial expressions, while individual Boos change theirs for a brief second if left alone for a while.

[[File:SML2 Boo.png|frame|left]]

Boos appear in ''[[Super Mario Land 2: 6 Golden Coins]]''. These Boos are relatively unchanged from the previous Boos from ''[[Super Mario Bros. 3]]''. Boos in this game are found in the [[Pumpkin Zone]]. A thrown [[Green Shell]] can defeat it. A variant named [[Terekuribō]], which resemble ghostly [[Goomba]]s, also appears in this game.

[[File:Boo 64.png|thumb|120px|left|A Boo in ''Super Mario 64'']]

[[File:SM64DS_BigBoo.png|thumb|175px|A Boo in ''Super Mario 64 DS'']]

Boos (also called '''Baby Boos'''<ref>Prima Bath. ''Nintendo 64 Game Secrets, 1999 Edition'' Prima's Official Strategy Guide. Pages 86 and 87.</ref>) make a starring appearance in the course [[Big Boo's Haunt]] in ''[[Super Mario 64]]''. A group of Boos can be found in the castle gardens (eight of which are holding [[Red Coin]]s in the DS version). After collecting twelve [[Power Star]]s, Mario is able to enter Big Boo's Haunt by going into the little cage that a certain Boo drops; this Boo will be somewhat bigger than the others. He also battles Big Boo three times here. Additionally, when Mario looks at the Boos, they attempt to hide by becoming partially transparent, but if Mario is not looking at them, they chase him. If they hit him, he loses two wedges of health. In the translucent Boo, the player can see a [[coin]] or a [[Blue Coin]]. To defeat them, a punch or kick from behind or the side is needed. They can also be defeated with a [[Ground Pound]] while he is not looking at them. When defeated, they give a Blue Coin, but the ones in the castle gardens give a normal coin instead. When defeated in the first mission, [[Go on a Ghost Hunt]], the Boos will say, "''Ghosts... ...don't... ...DIE! Heh, heh, heh! Can you get out of here... ...alive?''" when defeated. In addition, a Boo will appear in the hallway of the [[Peach's Castle|Mushroom Castle]] after twelve Stars are collected.

 

In ''[[Super Mario 64 DS]]'', eight Stars are needed to spawn a small Boo in the hallway, who holds a Red Coin. After fifteen Stars are collected, the small Boo is replaced by a Big Boo, which then allows Mario to enter Big Boo's Haunt. Sometimes, if the player is not Luigi, one particular Boo will wear a Luigi Cap. In the haunt, Mario can find a Luigi painting, which will take him to the [[Big Boo Battle]] level on the balcony. After defeating [[King Boo]] within, Mario gains the key to the room in which Luigi is imprisoned and proceeds to free him. In the English version of the game, King Boo is incorrectly referred to as "Big Boo." Yoshi cannot defeat Boos in this game. Ground-pounding yields no results, and eating them simply causes Yoshi to spit them back out. Fortunately, Mario, Luigi, or Wario can hit Boos with Ground Pounds.

While Boos do not appear in the original ''[[Super Mario Bros.]]'', Boos appear in ''[[Super Mario Bros. Deluxe]]'' as the main enemy in the "You VS. Boo" mode. The goal is to reach the [[flagpole]] before the Boo. After defeating Boo within a certain time frame, it flies away, and a [[Green Boo]] replaces it. After that Boo is defeated, a [[Red Boo]] takes its place, and finally, a Black Boo with a yellow outline appears. Each new Boo gets progressively faster than the one before it, meaning the plain White Boo is the slowest, while the Black Boo is the fastest and hardest to defeat.

[[File:SMS Boo Artwork.jpg|thumb|left|A Boo from ''[[Super Mario Sunshine]]'']]

Boos return in ''[[Super Mario Sunshine]]'', terrorizing the residents of [[Hotel Delfino]]. In this game, they move around in slow, swooping motions and do not care if Mario looks at them. They tend to go in Mario's general direction while turning invisible (aside from some distortion), but spraying them with [[F.L.U.D.D.]] causes them to slowly become visible again. These Boos can be defeated by being jumped on, making ''Super Mario Sunshine'' the only game outside of the ''Mario'' RPGs where jumping can defeat them. Boos in this game can also be eaten by Yoshi. They also disguise themselves as [[Yellow Coin]]s and [[Blue Coin]]s, which unlike the real ones do not spin. Boos can also disguise themselves as [[Shadow Mario]] while the real Shadow Mario runs from Mario, though they appear lighter than Shadow Mario, lack the [[Magic Paintbrush]], and do not have the theme music. When Mario approaches a disguised Boo, it laughs and bumps into him, though if it is sprayed beforehand it will start behaving like the other Boos. Like the other enemies, Boo's design is changed for this game, with drooping eyelids, blue circles surrounding their black pupils, and long, coiled tails. This is due to the fact that they are made from [[graffiti]].<ref>{{media link|ESMB Bowser Jr Graffiti.png|An excerpt of page 107 of the ''Encyclopedia Super Mario Bros.''}} The title of the box is 「クッパＪｒ．の落書き!」 which means ''The graffiti of Bowser Jr.!'' and the text says 「本作の敵キャラクターたちは、クッパJr.が落書きで生み出したという設定。そのため、水に弱かったり、デザインが他のシリーズと少々異なっていたりする。ヨッシーも、同様の理由で水に落ちると消えてしまう。」 which means ''This game's enemy characters are created by Bowser Jr.'s graffiti. That is why they are weak to water, and differ slightly in design from the rest of the series. Yoshi also vanishes if he falls in water for the same reason.''</ref>

 

The Boos in this game are led by [[King Boo (Super Mario Sunshine)|King Boo]]. Mario finds him in the basement of the hotel's Casino, and he has to battle him. He can defeat him by throwing a [[Chili Pepper]] at him and then throwing another piece of [[fruit]] at him. Mario has to do this three times before King Boo is defeated. [[Red Boo|Pink Boo]]s also appear and can be turned into a platform if sprayed by F.L.U.D.D. Also appearing inside the hotel are a new species, known as [[Sleepy Boo]]s. These Boos mostly appear to block passages. F.L.U.D.D.'s water does not affect them; they can be removed only by being eaten by [[Yoshi]].

[[File:NSMBDS Boo Sprite.gif|frame|left]]

Boos also appear in ''[[New Super Mario Bros.]]''. They are found mainly in Ghost Houses scattered throughout the game, as well as [[World 8-1 (New Super Mario Bros.)|World 8-1]]. They appear like they usually do, shy, and they act the same as in ''Super Mario Bros. 3''. They can only be defeated with a [[Shell]], a [[Super Star|Starman]], a [[Mega Mushroom]], or a [[Blue Shell]]. The game also introduces the [[Balloon Boo]], which are normal Boos who can suck up air, and become much bigger. [[Broozer]], the boxing ghost, first appears in this game as well. An icon of 2 Boos covers the progress map in Ghost Houses.

[[File:Mario_Seek.png|thumb|200px|Mario looking at a Boo in ''Super Mario Galaxy'']]

Boos make an appearance in ''[[Super Mario Galaxy]]'' and can be found in the [[Ghostly Galaxy]], the [[Bigmouth Galaxy]], the [[Deep Dark Galaxy]], and the [[Sand Spiral Galaxy]]. Boos act the same way that they did in previous games, such as hiding by turning transparent when Mario looks at them and then following Mario when he looks away. Boos can be defeated only when they are brought under a ray of light (including the Toad Brigade captain's helmet and the light emitted from shells while in the water) or by [[Rainbow Mario]] touching them. The spin attack, however, can throw a Boo around Mario, knocking it off course temporarily or into a light. Boos can also be found underwater in the [[Bigmouth Galaxy]] where they attack just by swimming back and forth, similar to [[Cheep Cheep]]s. In [[Deep Dark Galaxy]], in the secret mission, there is a large Boo that has a [[Power Star]] in it.  

 

[[Boo Mario]] also appears in this game. Mario has the same look as the other Boos, but retains his face when in his Boo form. He also wears his trademark cap on his head. If a Boo spots Mario while he is a Boo, it develops an attraction for him and follows him. If a Boo hits Mario, Mario loses the powerup, but does not lose any health.

 

An individual Boo named [[Spooky Speedster]] is found in two areas of the game. Mario must race him twice to win a [[Power Star]]. He is raced once in the Ghostly Galaxy and once again in the [[Boo's Boneyard Galaxy]]. This game also introduces a new kind of Boo, called the [[Bomb Boo]]; it is similar to a normal Boo, but is black with yellow eyes and can be grabbed by its tongue if Mario uses his spin attack on it.

Boos reappear in ''[[New Super Mario Bros. Wii]]'' in Ghost Houses throughout the game. They behave the same way as they did in ''New Super Mario Bros.'' and are invincible, unless the player has a [[Super Star|Star]] power-up. [[Big Boo]]s also reappear along with [[Broozer]]s. [[Boo Buddies|Circling Boo Buddies]] can also be found in a small amount of Ghost Houses in the game. Despite their concept art, they appear with a blue glow as opposed to plain white in this game, giving off a more spectral appearance. In the level selection screen, a single Boo will be watching Mario, and will taunt Mario as he enters. If Mario gets tossed out, the Boo will laugh. However, once the level is beaten, the Boo will cover its face for the rest of the game.

[[File:Boos and Big Boo SMG2.png|thumb|Boos alongside a [[Big Boo|Mega Boo]] in the [[Haunty Halls Galaxy]] in ''Super Mario Galaxy 2'']]

Boos reappear in the game ''[[Super Mario Galaxy 2]]''. They behave the same way they did in its predecessor. They are found in haunted levels such as [[Haunty Halls Galaxy]] and [[Boo Moon Galaxy]]. The underwater Boos from the predecessor also appear in this game, in the [[Battle Belt Galaxy]] and [[Slimy Spring Galaxy]]. [[Bomb Boo]]s and [[Big Boo|Mega Boo]]s also reappear. A variant named [[Octoboo]], which resemble ghostly [[Octoomba]]s, also appears in this game.

Boos later appear in ''[[Super Mario 3D Land]]''. In the game, they retain their normal battle strategy, which is chasing [[Mario]] when he looks away while sticking its tongue out. Boos in this game also momentarily disappear when hit with [[Fire Mario]]'s fireballs and [[Tanooki Mario]]'s tail whips. Boos also laugh in their original phonic from ''[[Super Mario 64]]''. Some Boos have [[Raccoon Mario|striped tail]]s; these are called [[Tail Boo]]s. They act like normal Boos, but when they stop moving when Mario looks at them, they will swing their tails once, which can damage Mario. Big Boos also appear during the game. Another species of Boo is also introduced, called [[Peepa]]s. They do not act like normal Boos, instead moving around a set position, and do not halt when Mario looks at them, as in ''[[Super Mario Galaxy]]''.

Boos, along with [[Big Boo]]s, return in ''[[New Super Mario Bros. 2]]'', with the same appearance and behavior as in ''New Super Mario Bros. Wii'', except they turn completely red when Mario faces them. They can be found in Ghost Houses along with other ghost enemies such as [[Peepa]]s and the new [[Boohemoth]]. All of these varieties, save for Boohemoth, can be defeated with a Star or [[Gold Flower]]. Boos can also be turned [[Gold Boo]]s with a [[Gold Ring]]. When gold, Boos float away from Mario, leaving a trail of coins behind them.

There are also Boos that push walls in a Ghost House, namely World 4's [[World 4-Ghost House (New Super Mario Bros. 2)|Ghost House]]. Here they push the wall either left or right and they do not stop when Mario looks at them.

====''New Super Mario Bros. U''====

[[File:BooNSMBU.png|thumb|left|Artwork from ''New Super Mario Bros. U''|100px]]

Boos, [[Big Boo]]s, and [[Boo Buddies|Circling Boo Buddies]] appear in the [[Wii U]] title ''[[New Super Mario Bros. U]]''. Their behavior is the same as that of past installments. Boos also have their own [[Enemy Course]] in the [[Soda Jungle#Haunted Area|haunted area]] of the [[Soda Jungle]], where a group of Boos appear in an area with various [[Donut Block]]s, and defeating them must occupy the [[Super Star]] located inside a [[Flying ? Block]]. They can also be defeated with a [[Baby Yoshi]].

====''Super Mario 3D World''====

 

====''Super Mario Maker'' / ''Super Mario Maker for Nintendo 3DS'' / ''Super Mario Maker 2'' ====

Boos reappear in ''[[Super Mario Maker]]'', ''[[Super Mario Maker for Nintendo 3DS]]'', and ''[[Super Mario Maker 2]]'' as enemies. They function the same as previous games. In the Course Maker, they can be placed as enemies, and can be shaken to turn into [[Boo Buddies]]. They can also be dragged onto a platform, turning them into [[Stretch]]es. Like many enemies, they can be enlarged by a [[Super Mushroom]] and be given wings, which the former will turn it into a Big Boo, and the latter will make them move much faster. They can be placed in [[Warp Pipe]]s, [[Bill Blaster]]s, [[Block]]s, and [[Track (object)|track]]s. In addition, adding Wings to a Boo Buddy makes the Boo Buddy move in and out. If a Boo is placed in a [[Koopa Clown Car]], the Koopa Clown Car stops and closes its eyes when it is looked at, and sneaks up on the player when looking away.

Boos appear in ''[[Super Mario Run]]'' in Ghost House levels. When Mario looks at them, they cover their eyes, and also float up and down. They attack Mario by quickly following behind him. Mario can defeat them by backflipping over them. In some levels, pressing the pink [[P Switch]] defeats Boos on-screen. They can drop [[Key]]s, [[Coin]]s, or [[Color coin]]s after they are defeated, and the object they contain inside of them can slightly be seen through them before they are defeated. In [[Dark and Stormy]], Boos are defeated when a lightning strike occurs. Stretches also appear in the game.

====''Super Mario Odyssey''====

Boos do not appear physically in ''[[Super Mario Odyssey]]'', making this game the first ''Super Mario'' game 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.

[[File:CartoonBoo.jpg|thumb|A Boo in the ''The Adventures of Super Mario Bros. 3'' episode "Reign Storm"]]

Boos make infrequent appearances in ''[[The Adventures of Super Mario Bros. 3]]'' television series, which depicts them as having a somewhat menacing appearance. They are depicted with red eyes and yellow teeth. Like in the game the show is based on, Boos work for Bowser and often aid him in causing trouble. An example of this is seen in the episode "[[Reign Storm]]," in which Bowser has several Boos terrorize the new Mushroom Shopping Mall. In this episode, they are referred to as "Boo Diddlys."

[[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"]]

In ''[[Super Mario World (television series)|Super Mario World]]'', Boos, who are completely redesigned, appear in the episodes "[[Ghosts 'R' Us]]," in which a gang of Boos, as well as a Big Boo, appears to chase [[Yoshi]] through [[Wizenheimer]]'s [[haunted house (Super Mario World television series)|haunted house]]; "[[The Night Before Cave Christmas]]," in which they scare Yoshi away; and "[[The Yoshi Shuffle]]," in which several Boos appear in the audience during the episode. They are never referred to by name, instead simply being referred to as "ghosts." They more closely resemble their in-game sprite.

[[File:Capers.jpg|thumb|Boos chasing Luigi on the front cover of [[Koopa Capers]], the fourth of the ''Nintendo Adventure Books'']]

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 it 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 Topsy-Turvy''====

Boos appear again in ''[[Yoshi Topsy-Turvy]]''. In this game, they only appear mission 6-7, with Big Boos being more common. They follow the same tactics as normal, and are given their laugh from preceding releases.

[[File:SMK Boo Item Box Sprite 1.png|frame]]

[[File:SMK Boo Item Box Sprite 2.png|frame]]

Boos made their first appearance in the ''[[Mario Kart (series)|Mario Kart]]'' series in ''[[Super Mario Kart]]'' as items exclusive to "2 Player" mode, under the name '''"Ghosts"'''. When the player uses it, they will become transparent temporarily, while the "Ghost" steals the opposing player's item, if available. They also appear as background elements in [[Ghost Valley 1|the three]] [[Ghost Valley 2|Ghost Valley]] [[Ghost Valley 3|courses]], where they laugh when the player drives by.

Boos (or '''Ghost Bonuses'''<ref>''Nintendo Magazine System'' (AU) Issue #49, page 39.</ref>) return as a usable item in ''[[Mario Kart 64]]''. They can be obtained if the player is in the top two positions. When activated, the Boo selects a racer with the best item in reach, and steals the item and gives it to the player that released it. At the same time, the player obtains total invisibility and invincibility for a short period of time. While invisible, the player can pass the items, the course obstacles and the other racers more easily by simply going through them. If no other players possess items, the Boo will return empty-handed. Boos also appear in [[Banshee Boardwalk]] and the image of one appears in neon lights in [[Rainbow Road (N64)|Rainbow Road]], both as background elements.

[[File:MKSC Boo Alternate Artwork.jpg|thumb|A Boo from ''Mario Kart: Super Circuit'']]

[[File:Broken Pier MKSC icon.png|thumb|left|Boos attacking [[Toad]] on Broken Pier from ''Mario Kart: Super Circuit'']]

Boos appear as items again in ''[[Mario Kart: Super Circuit]]''. When activated, they can also slow down the leading racer. Starting in this game, if a CPU racer uses a Boo, it can also steal items from the player and make the player lose Coins.

 

Boos also appear in two new courses, [[Boo Lake]] and [[Broken Pier]]. At Boo Lake, Boos hold candles which guide the player through the track. On Broken Pier, they attack the players and take their [[Coin]]s.

Boos do not appear as items in ''[[Mario Kart: Double Dash!!]]''. However, Boos, as well as the Boolossus' gold frame portrait, appear in the [[Luigi's Mansion (GCN)|Luigi's Mansion]] battle course. Also, King Boo makes his ''Mario Kart'' debut as a playable character.

 

Boos appear as items in the arcade game, ''[[Mario Kart Arcade GP]]''. A Boo appears as a basic item. It causes whoever is hit by it to slow down temporarily. There is also a new item called the '''Triple Boo'''.  

[[File:MKDS Boo Sprite.png|thumb|left|Boo item from ''Mario Kart DS'']]

In ''[[Mario Kart DS]]'', Boos reappear as items (with the name of '''Boo Hoo''' in the European instruction manual<ref>[https://cdn02.nintendo-europe.com/media/downloads/games_8/emanuals/nintendo_ds_21/Manual_NintendoDS_MarioKartDS_EN.pdf ''Mario Kart DS'' European English instruction manual, page 12.]</ref>). They can be obtained if the player is anywhere from 3rd to 7th place. The only differences are, they do not slow down the leading racer, and they no longer steal the best item in reach. Instead, they just steal the nearest racer's item. Additionally, while using the Boo item, the player will not be slowed down while driving on off-road surfaces, allowing various shortcuts to be made. Some pictures of Boos from the game, ''[[Luigi's Mansion]]'', appear in the [[Luigi's Mansion (place)#Mario Kart DS|Luigi's Mansion]] race course. [[Banshee Boardwalk]] reappears as a race, along with the Boos. They do not do anything that affects the racer; they just laugh when a racer drives by.

 

[[File:YoshiPark2.png|thumb|Boos along with other [[Ghost (Luigi's Mansion series)|ghosts]] on the thumbnail for [[Yoshi Park 2]] from ''Mario Kart Arcade GP 2'']]

Boos reappear in the arcade game, ''[[Mario Kart Arcade GP 2]]''. Like what they do in ''Mario Kart Arcade GP'', they slow down the leading racer. Though, the Triple Boos do not appear in this game, even though it appears in the predecessor.

[[File:Ghost Valley 2 MKWii.png|thumb|left|Boos from the track Ghost Valley 2 in ''Mario Kart Wii'']]

Much like in ''Mario Kart: Double Dash!!'', Boos do not appear as items in ''[[Mario Kart Wii]]'', but [[King Boo]] appears as a playable character. However, Boos do appear in a returning course, Ghost Valley 2. Like their original appearance in the track, Boos only laugh when racers drive by, but they eventually disappear. Boo also makes a cameo in Bowser's Castle. At the end of the track Boo's ''Mario Party 7'' artwork can be seen along with Dry Bones' artwork.

[[File:MKTTC LM.png|thumb|Boos seen in the Luigi's Mansion track from ''Mario Kart 7'']]

In ''[[Mario Kart 7]]'', Boos appear in the returning track, [[Luigi's Mansion (DS)|Luigi's Mansion]], in place of the portrait ghosts. They will pop out of their paintings when the drivers race by them. They also appear as spectators on [[Toad Circuit]].

 

[[File:MKAGPDX Boo.png|thumb|left|Boo item from ''Mario Kart Arcade GP DX'']]

In ''[[Mario Kart Arcade GP DX]]'', Boos return from ''Mario Kart Arcade GP 2'' as items.

In ''[[Mario Kart 8]]'', Boos appear as obstacles on [[Twisted Mansion]]. If aimed correctly, the players can land on the Boos floating around near the gliding section. They also possess [[Hammer Knight]]s near the end of the track.

In ''[[Mario Kart 8 Deluxe]]'', [[King Boo]] is again a playable character, and Boos can also be seen floating around on [[Luigi's Mansion (GCN)|<small>GCN</small> Luigi's Mansion]]. Boos also appear as items again, acting as they do in ''Mario Kart DS'', though the mechanics are slightly different. Unlike in that game, Boo users are still slowed down by off-road surfaces. Boos immediately steal an item from a random racer in front of the user, and invincible or other invisible players are not immune; the Boo will bring back a Mushroom if there is nothing to steal. The Boo is visible, both when it steals an item and when it gives the stolen item to the user. It takes a couple more seconds to deliver the item back to the player, however. Only one Boo can be in play at a time; once it brings back an item, another can appear in item boxes again, even while another player is still invisible. Lastly, due to the way deployed items work, a Boo is able to steal any timed or multiple usage item, except for a [[Crazy Eight]], or a [[Piranha Plant (potted)|Potted Piranha Plant]] and Bullet Bill already in use. Doing so will always give the user a fresh version of the item.<ref>Mankalor (May 8, 2017). [https://youtu.be/OUdaqb7Cj2I Mario Kart 8 Deluxe Tips - Boo Item Analysis]. ''YouTube''. Retrieved May 9, 2017.</ref>

[[File:MKT Boo Wooden Cutout.png|thumb|right|A wooden cutout of two Boos in ''Mario Kart Tour'']]

Boos reappear in ''[[Mario Kart Tour]]'' in the courses DS Luigi's Mansion and SNES Ghost Valley, where they act the same as they did on those courses in previous games. In both courses, [[wooden cutout]]s of Boos appear.

 

During the [[Halloween Tour (2020)|2020 Halloween Tour]], [[jack-o'-lantern]]s are scattered throughout the courses. Some jack-o-lanterns have Boo faces.

Boos reappear in ''[[Mario Kart Live: Home Circuit]]'' in [[Boo Fortress]], frightening racers who hit them.

In ''[[Super Mario Adventures]]'', a horde of Boos appear to attack Mario and Luigi when they are tricked into a haunted house by Bowser and the Koopalings. Mario and Luigi become trapped by the Boos and a Big Boo, who are held at bay by the bros staring at them in the face. Eventually, nearing exhaustion, Mario races to a nearby room, dragging Luigi while being chased by the Boos. Upon barging into this room, the Boos and Big Boo find Mario [[Dr. Mario|dressed as a psychiatrist]] with Luigi as his nurse. After some talking, Mario and Luigi manage to reform the Boos and the Big Boo, while learning they were bullied in their youth (which is why they act so nasty to everyone). These Boos and their Big Boo leader were last seen happily waving goodbye to Mario, Luigi and Yoshi as they left the haunted house, which the Boos led them out of.

Boos also make an appearance at Peach's wedding.

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

Boos make an appearance in the ''[[Super Mario All-Stars]]'' remake of ''[[Mario Bros. (game)|Mario Bros.]]'', where they replace the [[Fireball (obstacle)|Fireball]]s in the [[Mario Bros. (game)#Super Mario All-Stars|Battle Game]] found in the main menu of ''[[Super Mario Bros. 3]]'' but not in the [[Mario Bros. (game)#Super Mario Bros. 3|2 Player Game's battle mode]].

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

Boos also appear in the game ''[[Hotel Mario]]'' under the name '''Boo Buddies'''<ref>''Hotel Mario'' instruction book, page 16.</ref>. There are two types of Boos in this game. One type stays visible but does not hurt Mario until it turns transparent. The other type of Boo uses the traditional attack method and turns invisible when looked at, and attacks Mario when his back is turned.

Boos also make a cameo appearance in the [[Game Boy]] game, ''[[Mario's Picross]]''. They appear in one of the pictures in the "Early Picross" stage in level 6C. The other character that appears in the "Early Picross" stage is [[Mario]], who appears in level 6H. Like their first appearance, ''[[Super Mario Bros. 3]]'', they appear under the name '''Boo Diddly'''.

===''Mario Clash''===

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

Boos<ref>''Mario Clash'' Japanese instruction booklet, page 20.</ref> (misnamed "Big Boo" in the English manual<ref name=ClashBoo>''Mario Clash'' English instruction booklet, page 21.</ref>) make appearances in the [[Virtual Boy]] game, ''[[Mario Clash]]'', where they are among the target enemies. In this game, Mario is able to attack a Boo from the side. Boos can become transparent by becoming dark like the screen, which causes them to become invulnerable, with [[Green Shell|shell]]s simply passing through. For some reason, the English manual also refers to the Boos using feminine pronouns, similar to [[Cheep Cheep]] in the original ''[[Super Mario Bros.]]''<ref name=ClashBoo/>

{{br}}

[[File:SMRPG Big Boo Artwork.png|thumb|Artwork of The Big Boo from ''Super Mario RPG: Legend of the Seven Stars'']]

Boos return during the events of ''[[Super Mario RPG: Legend of the Seven Stars]]''. The English translation erroneously calls them "The Big Boo". In the Japanese version in fact they are just called Teresa. These Boos, like other Boos that appear in previous games, hide behind their arms when stared at. However, some of The Big Boos teleport around the room, attempting to scare Mario and his friends. The Big 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. Big Boos have no physical defense, making them extremely weak enemies (even a [[Goomba]] has three defense points). However, The Big Boos make up for their lack of defense with high evasion, meaning that most attacks against a The Big Boo will miss. In battle, The Big Boos command powerful lightning magic, including the attacks [[Lightning Orb]] and [[Bolt (move)|Bolt]]. The Big Boos also know the special attack [[Scream]], which cuts a party member's [[fear|attack and defense in half]]. When not using magic, a The Big Boo will 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 [[Li'l Boo]]s, which are the same size as normal Boos 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>''Super Mario RPG: Legend of the Seven Stars'' English instruction booklet, page 41.</ref> One The Big Boo lives in [[Monstro Town]] as part of the [[3 Musty Fears]], while another, simply named Boo, appears as part of one of [[Dr. Topper]]'s puzzles.

===''Super Mario-Kun''===

[[File:Boo SuperMarioKun 8.jpg|thumb|Boo as it appears in ''Super Mario-Kun'']]

[[File:SMK25.jpg|thumb|left|Lady Bow as seen on the cover of ''Super Mario-Kun'' issue 25]]

Boos make appearances in some of the ''[[Super Mario-Kun]]'' comics. A Boo appears on the cover of the sixteenth issue. This issue 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.

Boos (called "Boo Buddies") appear in the Modern version of ''[[Vermin]]'' in ''[[Game & Watch Gallery 2]]''. When [[Yoshi]] looks in the general direction of them, they refuse to move. When Yoshi looks away, they move towards the eggs. They only appear in groups of two or just one.

A Boo appears in the Modern versions of ''[[Donkey Kong 3 (Game & Watch)|Donkey Kong 3]]'', ''[[Mario's Cement Factory]]'', and ''[[Boxing]]'' in ''[[Game & Watch Gallery 4]]''. In ''Donkey Kong 3'', if Mario or Donkey Kong turns his back, it will slowly come closer to the player that it is closer to. If it gets close enough, the Boo will either scare Donkey Kong and award the player points (single-player mode only) or scare Mario and give the player a miss. In ''Mario's Cement Factory'', a Boo will fly into the two containers on the second floor, clogging them up. The player does not receive any points for removing the Boo. In ''Boxing'', one of the opponents [[Luigi]] faces is a [[Big Boo]], who uses a regular Boo as a boxing glove.

Boo has been a major character in the ''Mario Party'' series, from being a thief for hire, to being a playable character.

[[File:CrazyCutter.png|thumb|left|Players cutting out Boos in Crazy Cutters from ''Mario Party'']]

Boos make minor appearances in ''[[Mario Party]]''. Their voices can be mimicked by one of the items: the [[Talking Parrot]]. Boos also appear in each of the game's board maps, excluding [[Peach's Birthday Cake]]. On the boards, they steal [[Coin]]s or [[Star (Mario Party series)|Stars]] from opponents, and they are willing to steal a few coins for free from any player, although they will steal the number of coins at random. They also ask for 50 coins to steal a Star. If the player tells Boo that they do not want to steal anything, Boo will say "''Don't feel so guilty. Ha ha ha!''" Additionally, after the Luigi's Engine Room board is completed, a Boo, [[Koopa Troopa|Koopa]], and a [[Toad]], along with the two runner-ups, surround the victor and congratulate them. Boos also appear in several mini-games, including [[Pedal Power]] and [[Running of the Bulb]], and as one of the shapes the player can cut in the minigame, [[Crazy Cutter]].

Boos make several appearances in ''[[Mario Party 2]]''. In it, they steal Coins or Stars as they did in the first game. However, Boo charges 5 coins to steal coins instead of a free steal; and steals much more than in the first game. Additionally, an item called the [[Boo Bell]] appears. When a player obtains it, they can ring for a Boo to come. The Boo that comes to the player's side is asked to steal Coins or Stars, depending on how much the player can afford. If the Boo is sent to steal Coins from an opponent, 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 also appears in the battle minigame, [[Day at the Races]], along with the others racers, [[Whomp]], [[Thwomp]], and [[Bob-omb]]. The Boo can disappear and then reappear in a further spot on the racetrack. However, it gets its face stuck in the ground sometimes, causing it to stop for a short period of time.

Boos also appear in ''[[Mario Party 3]]''. Like in their previous appearances, they are not major characters in the game. They are among the Duel Partners in the [[Mario Party 3#Duel Mode Partners|Duel Mode Partners]]. It is [[Yoshi]]'s default partner, and when an opponent attacks, Boo can counterattack for equal damage, unless it was defeated by a [[Thwomp]]. Boo's attack is two, its health its one, and its salary is three coins.

 

Boos also appear in the unlockable party board, [[Waluigi's Island]]. Whenever a player runs into a Boo, it shows them to two paths. One of the paths is rigged. If the player chooses the rigged path, they are sent back to the start. If they choose the correct path, they continue on the board. In addition, Boos appear on all of the other boards, [[Chilly Waters]], [[Deep Bloober Sea]], [[Spiny Desert]], [[Woody Woods]], and [[Creepy Cavern]], serving the same function as in the previous games. On the board map, a picture of them can be seen next to a grave. They also return with the Boo Bell. Boos are also in the minigames [[Curtain Call]], [[Stacked Deck]], [[Three Door Monty]], and [[Crowd Cover]]. Two portraits of a Boo can also be seen in [[Locked Out]].

[[File: Booparty4.jpg|thumb|175px|left|The sorcerer Boo from ''Mario Party 4'']]

In ''[[Mario Party 4]]'', a Boo plays a major role as the host for [[Boo's Haunted Bash]]. This is the first game where the Boo uses its modern design. This Boo wears a wizard's hat and cape, and like the other hosts in the game, it is the character to reward the player with a Star. Multiple Boos also appear on this board as background characters. A particularly surly one controls the Item Shop. Another one owns the [[Mystery Train]], but it only gives out rides to the Boneyard if a [[Red Boo]] is not in its presence. Two side-games involving Boos requires a [[Mini Mushroom]]. One of them has the player pressing one of the keys of the Horn of Plenty to get one of three randomly chosen items. The second one has the character on a piano. They have to press the correct key at the right time until the end of the side-game to get a certain amount of Coins. A question mark space activates a Boo clock. If three people land on them, Big Boo will appear. Big Boo is basically an upgraded version of the Boo House; he targets all players instead of one. The caped Boo is also the fourth host of the Reversal of Fortune, who oversees what is given.

 

Boos also appear on every other board in the game, stealing coins and Stars for the player at a shop called the [[Ghost House#Mario Party series|Boo House]] in the same manner as Boos' previous appearances in the ''Mario Party'' series.

 

 

In [[Long Claw of the Law]], a Boo is one of the possible characters that needs to be collected.

[[File:Boo Artwork - Mario Party 5.png|thumb|125px|Boo from ''Mario Party 5'' playing [[Coney Island (minigame)|Coney Island]]]]

''[[Mario Party 5]]'' marks the first game in the ''Mario Party'' series where Boo is a playable character in Party Mode. He is one of the new characters, the others being [[Koopa Kid]] and [[Toad]]. Boo's partner in the game is [[Koopa Kid]]. Since Boo is playable, he does not make any major background appearances. His previous role on the boards is now fulfilled by [[Chain Chomp]].

A Boo reappears as playable character in ''[[Mario Party 6]]''. In the game, there is also an orb called [[Boo Away Orb]], which protects the player from a [[Red Boo]]. Red Boos also appear in the minigame [[Boo'd Off the Stage]] and [[Boonanza!]]. Red Boos also appear two boards, [[Towering Treetop]] and [[Castaway Bay]] where they let players steal coins and stars from others at night, similar to the Boo House in ''Mario Party 4''. This game also marks the third appearance of Red Boos in the ''Mario Party'' series.

Boos appear in ''[[Mario Party Advance]]'' as supporting characters. They appear in a few minigames, including [[Boo-Bye]]. In this minigame, regular Boos appear alongside Red Boos and Blue Boos. They also appear in [[Spooky Spike]], in which one Boo serves volleyballs to the player, [[Floor It!]], in which Boos are one of the possible passengers that must be brought to their respective floor, and [[Porta-Gust]], in which the player can suck up Boos into a vacuum.

One of them, [[Boo (Mario Party Advance)|Boo]], appears alongside some other Boos in the [[Boo Cemetery]], where they are main characters in the quest [[True-Blue Boo]].

[[File:Dry Bones and Boo Artwork - Mario Party 7.png|thumb|120px|Boo and Dry Bones from ''Mario Party 7''. This artwork is also found at ''Bowser's Castle'' in ''Mario Kart Wii''.]]

''[[Mario Party 7]]'' marks the third ''Mario Party'' game where Boo is playable. It also marks [[Dry Bones]]' first playable appearance, who is Boo's partner throughout the game. Red Boos appear in the game, too. Red Boos appear in a few minigames such as [[Ghost in the Hall]]. In this minigame, Red Boos try to scare the players. Oddly, the Red Boos also try to scare Boo, if Boo is one of the characters. Boo shares the same special orb with Dry Bones, the [[Magic Orb]]. It allows them to double their dice roll during the next two turns and turns them invisible, making them immune to traps.

In ''[[Mario Party 8]]'', Boo is a playable character for the fourth time in the ''Mario Party'' series. Boo's partner is Dry Bones, again. Red Boos appear in some minigames such as [[Boo-ting Gallery]]. ''Mario Party 8'' also marks the first appearance of [[King Boo]], who is the board host of [[King Boo's Haunted Hideaway]]. In order to get a Star, the player must find the room King Boo is hiding in and give him ten coins. There are three rooms, two of which contain a trap hole. If the player finds one of these rooms, several Red Boos will throw them in, forcing the player to start back at the beginning. When the player gets a Star, King Boo will rearrange the mansion's rooms. Red Boos appear as owners of the item shops.

Boo is not a playable character in ''[[Mario Party DS]]'' and plays no part in board play, but appears as an unlockable figure. They also appear in the minigames [[Boo Tag]], and [[Peek-a-Boo (minigame)|Peek-a-Boo]]. In Boo Tag, a Boo tags a player. The tagged player must try to get rid of the Boo by running into another player. The player that spent the least amount of time with the Boo wins. In Peek-a-Boo, the players must find the wanted Boo. A lot of different Boos appear in outfits, such as hats. Several of the wanted Boo appear, and once they are all gone, the game is over. The team that won the most Boos wins.

[[File:MP9 Boo's Horror Castle Toad.jpg|thumb|left|A Boo in ''Mario Party 9'']]

Boo does not return as a playable character in ''[[Mario Party 9]]'', however [[King Boo]] is the boss of [[Boo's Horror Castle]]. Normal Boos also appear on the board. When the player passes a Boo portrait, a Boo will emerge and chase after the player. These Boos will move three spaces after each turn, and if a Boo catches up to the players (or vice versa), the current captain will lose half of all of their [[Mini Star]]s.

 

During [[King Boo's Puzzle Attack]], whenever King Boo's health is depleted halfway, he sends Boos to attack the player. If the player's cursor touches a Boo, they are temporarily stunned. King Boo only sends one Boo at a time.

[[File:Boo Artwork (alt) - Mario Party Island Tour.png|thumb|left|Boo from ''Mario Party: Island Tour'']]

[[File:BooMPIT icon.png|frame]]

Boo returns as a playable character in ''[[Mario Party: Island Tour]]''. This is the fifth time that Boo is playable, the first time he is playable on a handheld ''Mario Party'' game, and he is the first character in the series to be removed as a playable character in a main installment of the series and then return in a later installment.

Boo reappears in ''[[Mario Party 10]]'' as a non-playable character. Whenever the player reaches [[Boo (area)|a certain spot]] in the board [[Haunted Trail]], Boo appears and steals five Mini Stars from a specific player for an indefinite number of turns. Boo will continue to harass the player until passed off to another player via a [[Boo Space]] or driven towards a [[Streetlight]]. Boos also appear in the minigame [[Boo Burglars]], as enemies the players must examine, and appear as a balloon in the minigame [[Balloon Blast Bash]]. Several Boos also make cameos in the [[Luigi Board]].

In ''[[Mario Party: Star Rush]]'' Boo has a special mode called Boo's Block Party. Players can participate in a single-player endless mode for a high score or compete in a one-on-one versus mode. When players use the Boo [[amiibo]] in Boo's Block Party, four Boos appears in the background; two on the top screen, two on the Touch Screen. If players tap the Boo amiibo in the Mario Shuffle mode, players can use Boo in that mode. They also appear in the [[Haunted Hallways]] and [[House of Boos]] minigames.

In ''[[Mario Party: The Top 100]]'', Boo appears in minigames such as [[Slot Trot]] from ''Mario Party 6'' and [[Jigsaw Jumble]] from ''Mario Party 9''. However, in Minigame Match, Boo appears as an item via [[Boo Bell]].

Boo returns as a playable character in ''[[Super Mario Party]]'', which is his sixth playable appearance in the ''Mario Party'' series. Because of his status as a playable character, [[Lakitu]] takes his role as the one who steals coins or Stars from the earlier ''Mario Party'' installments. His Boo Dice Block consists of two of each -2 coins, 5, and 7.

{{mgtt-infobox

|name=Boo

[[File:Boovalley.jpg|thumb|left|Artwork of Boo Valley from ''Mario Golf'']]

In ''[[Mario Golf]]'' for the [[Nintendo 64]], Boos show where the wind blows by facing its direction in relation to the camera angle. They do not appear if there is no wind. Hole 2 of [[Mario's Star (golf course)|Mario's Star]] is designed after Boos. Also, Boos appear in the artwork for one of the courses, [[Boo Valley]].

Boo is one of the unlockable characters in ''[[Mario Golf: Toadstool Tour]]'', the others being [[Bowser Jr.]], [[Shadow Mario]], and [[Petey Piranha]], and is the only unlockable character in this game that appeared in the opening clip. In [[Bowser Badlands]], Boos affect the trajectory of balls hit through them. Boos once again reprise their role of showing the wind direction, but they have another role; if a player delays in starting their swing, then two Boos carry a sign and float across the screen. These signs describe basic gameplay tips, but some are rather taunts to the player.

[[File:BooHoleInOne.jpg|thumb|Boo getting a [[Hole-in-One]] in ''Mario Golf: World Tour'']]

Boo returns in ''[[Mario Golf: World Tour]]'' as a playable character, this time being available from the start. Boos also appear in Hole 4 of [[Bowser's Castle (golf course)|Bowser's Castle]] floating in the sky alongside [[King Boo]]. For this installment, a "blowing cloud" is used instead of a Boo to indicate wind speed and direction.

Boo appears in ''[[Mario Tennis (Nintendo 64)|Mario Tennis]]'' for the [[Nintendo 64]], marking his first playable role. He is classified as a tricky character, the only other character of this class being [[Koopa Paratroopa|Paratroopa]]. He is also a default character. Most of the playable characters have courts named after them. However, Boo does not have his own court.

====''Mario Tennis'' (Game Boy Color)====

[[File:Boo blast.png|thumb|A Boo in the minigame [[Boo Blast (minigame)|Boo Blast]] from ''Mario Tennis'' (Game Boy Color)]]

A Boo makes a cameo appearance in ''[[Mario Tennis (Game Boy Color)|Mario Tennis]]'' for the [[Game Boy Color]]. They can be seen in the audience at [[Peach's Castle]].

====''Mario Power Tennis''====

[[File:MPTBoo.PNG|thumb|135px|left|Boo from ''Mario Power Tennis'']]

Boo also appears in ''[[Mario Power Tennis]]'' where it is a playable character. When it 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 its racket while laughing. Boo's offensive power shot is the [[Boo Blast (move)|Boo Blast]] and its defensive power shot is the [[Boo Brigade Return]].

====''Mario Tennis Open''====

Boo reappears in ''[[Mario Tennis Open]]'', where he is again a playable and starting participant. He is one of the only two Tricky characters alongside [[Bowser Jr.]].

====''Mario Tennis: Ultra Smash''====

[[File:BooMTUS.jpg|thumb|left|Boo in ''Mario Tennis: Ultra Smash'']]

Boo appears in ''[[Mario Tennis: Ultra Smash]]'' as a default playable character. He is once again a Tricky character.

Boo returns as a playable character in ''[[Mario Tennis Aces]]''. Like in previous ''Mario Tennis'' games, Boo is classified as a Tricky character. His [[Trick Shot]]s are Roundabout and Through It All, while his [[Special Shot]] is Illusion. Boo also has unlockable alternate costumes, coming in the form of visors, that can be unlocked by playing the “Boo Hunt” co-op challenge. In this challenge the player must hit boos at the other side of the court to get coins. The visors came in Blue, Green and Purple and require 2,500 coins, 10,000 coins and 20,000 coins respectively.

Boos appear in ''[[Paper Mario]]'' as friendly but tricky characters. White Boos live in [[Boo's Mansion]], and yellow Boos live at [[Gusty Gulch]]. Their princess 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. Boos have prepared some puzzle 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.

In addition, a Boo appears after Mario got the [[Super Boots]] and tells him how to get the [[Star Piece (Paper Mario)|Star Pieces]] underground. And 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 appears to open the gate to Gusty Gulch under the command of Bow.

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

In the basement of [[Tubba Blubba's Castle]], a yellow 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]], 3x2 peasant Boos appear in front of [[Tubba Blubba's Castle]] and, seeing Mario and [[Lady Bow|Bow]] get out and [[Tubba Blubba]] chasing, help the co by blocking the door.

After Mario defeats [[Bowser]], two Boos come to [[Peach's Castle]] to see the party, one white and one yellow. The white one says he comes to see [[Lady Bow]] in her finery. He thinks that Bow is prettier than [[Princess Peach]]. The yellow one says he's 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.

In ''[[Paper Mario: The Thousand-Year Door]]'', Boos are enemies for the first time in the series. They 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 Shroom]]. If Mario is wrong the Boo will give him one [[coin]]. Upon returning 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#Paper Mario: The Thousand-Year Door|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 [[List of e-mails in Paper Mario: The Thousand-Year Door#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]].

=====Field Tattle=====

[[File:Mansion patrol.png|thumb|left|Boos in the minigame [[Mansion Patrol]] in the Flipside Arcade from ''Super Paper Mario'']]

[[File:SPM Boo Catch Card.png|thumb|Boo's [[Catch Card]]]]

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]]

Boos return in ''[[Paper Mario: Color Splash]]'' as enemies who can be fought in the parallel universes of [[Vortex Island]], [[Lighthouse Island]] and [[Fortune Island]]. 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.

[[File:OrigamiBoo.jpg|thumb|right|An origami Boo as seen in ''Paper Mario: The Origami King'']]

[[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 [[Bone Goomba]]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 Paratroopa]]s by day. A Paper Macho Boo is also featured as one of the seven opponents on [[Scuffle Island]].

[[File:LMBoo.jpg|thumb|A Boo in ''Luigi's Mansion'']]

[[File:Luigi%27sMansionBoo3DS.png|thumb|Luigi following a Boo in the Nintendo 3DS remake.]]

In ''[[Luigi's Mansion]]'', Boos are the main antagonists. This game also introduces the Boo leader, [[King Boo]]. King Boo sends a letter to Luigi, stating that he had won a mansion in a contest. However, Luigi does not enter any contest, but pays no attention, and heads off. Mario goes on ahead, but gets captured by the King of the Boos, [[King Boo]]. Luigi has to rescue him from the Boos, using [[Professor Elvin Gadd|E. Gadd]]'s [[Poltergust 3000]]. Luigi manages to find his brother, stuck in a painting. He ends up having to battle King Boo in order to rescue Mario. King Boo sends them to the roof of the mansion, and uses a Bowser suit to battle him. However, the suit's head could come off once a spikeball was thrown at him, and King Boo would float out, leaving him open for Luigi's Poltergust 3000. After taking away all of his 500 HP, King Boo is turned into a painting, and Mario is restored back to his normal self. However, King Boo manages to escape by unknown means and reappears in several future ''[[Mario (franchise)|Mario]]'' games.

 

There are [[List of Boos in Luigi's Mansion|50 Boos]] (51 including King Boo) which Luigi must suck up in the Poltergust 3000. Of these, 15 of them are [[Mini Boo|smaller one]]s that make up the portrait ghost [[Boolossus]], with King Boo as the final Boo. Unlike the other ghosts in the game, Boos will appear in a room, even when the lights are on. When Luigi attacks them, they usually run away, but occasionally twirl into him to cause damage. All of the 36 Boos, excluding King Boo and counting Boolossus as one Boo, have puns in their names.

 

The Boos in ''Luigi's Mansion'' seem to be the reverse of the Boos in the ''Super Mario'' series: while the Boos in the ''Super Mario'' series sneak up on Luigi when he is not looking and then disappear/hide when he looks at them, the Boos in ''Luigi's Mansion'' (excluding King Boo and Boolossus) hide when Luigi's not looking at them and then they face Luigi when he finds them. One of the Boos, PeekaBoo, references the fact that Boos are notorious for hiding.

[[File:Boo LMDM.jpg|thumb|175px|left|A Boo in ''Luigi's Mansion: Dark Moon'']]

Boos appear in ''[[Luigi's Mansion: Dark Moon]]''. They have names that play on "Boo" as in the first game. [[King Boo]] appears, having a similar appearance to that of his debut. They have the ability to create [[Spirit Ball]]s which can make objects invisible until exposed with the [[Dark-Light Device]]. All of the regular missions in the game have a Boo in an object that is invisible, and Luigi must find it by revealing the invisible object with the Dark-Light function of the [[Poltergust 5000]]; the Boo appears after the revealed Spirit Balls have been vacuumed up. However, not all Boos are hidden in invisible objects.

 

To capture a Boo, Luigi must expose it with the Dark-Light, vacuum and pull on the Boo's tongue, and release it with the {{button|3ds|A}} Button, damaging the Boo as it bounces around the room. When it reaches 0 [[Heart Point|HP]], the Boo can be sucked up; it sticks onto the nozzle, and Luigi presses the Poltergust 5000 against the ground to shove it inside. When Luigi returns to the [[Bunker]] after completing a mission, any captured Boos are sent to the Boo Canister in the [[E. Gadd's Vault#Boo Canister|Vault]]. After all Boos in a mansion have been captured, a bonus mission is unlocked for the corresponding mansion. There are a total of [[List of Boos in Luigi's Mansion: Dark Moon|32 Boos]], 33 if counting King Boo, 10 of which merge into the [[Big Boo]] fought in the [[Treacherous Mansion]].

[[File:LM3BooArt.jpg|thumb|175px|right|A Boo in ''Luigi's Mansion 3'']]

Boos return in ''[[Luigi's Mansion 3]]''. Like in previous entries, they have "Boo"-inspired names, and [[King Boo]] returns as the main antagonist.

There is one Boo found on each floor (except for the [[Master Suite]]), which appears after Luigi has obtained that floor's elevator button. The exact location of each Boo is randomised. To help find a Boo, [[Gooigi]] will begin to vibrate, corresponding with the player's controller, when next to the room with the Boo in it. There is also an item in the game known as a [[Boo Finder]], which reveals the location of a single Boo. Once Luigi enters the room with the Boo, the music will change and he must uncover the object with the strongest vibrations, which causes the Boo to appear and seal all exits until caught. If a wrong object is uncovered, the Boo will launch a swarm of bats at Luigi and flee to a different room. Once revealed, Boos attack by either spinning towards Luigi to deduct 20 HP or by throwing a [[Bomb (object)|bomb]] at him. To capture the Boo, Luigi must expose it with the Dark-Light device, then pull on its tongue and slam it repeatedly. All Boos have 20 HP.

[[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]]. 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.

Boos appear in the main game and in ''Minion Quest: The Search for Bowser'' from ''[[Mario & Luigi: Superstar Saga + Bowser's Minions]]''. Boos are flying troopers, and attack by ramming into enemies. Their [[Special Skill (Mario & Luigi series)|Special Skill]], Evasion Cloak, allows them to increase their evasion, depending on how filled the meter that is shown becomes. [[Captain Boo]] appears as a playable captain in the game. When a Boo appears as a captain, they are able to attack the other captain from behind, using [[Sneak Attack]].

During the events of ''[[Mario & Luigi: Partners in Time]]'', Boos appear in [[Bowser's Castle]] of the past. Mario, Luigi, [[Baby Mario]], and [[Baby Luigi]] meet a lot of them while trying to reach the end of Baby Bowser's Castle. In the field, Boos attack the same way as they did in ''Mario & Luigi: Superstar Saga'', but in-battle they fight differently, and have significantly decreased defense. They cover their faces, but when they start to attack, the Boo would take one of its hands off one of its eyes, showing who it is about to attack. If it shows its right eye, it will attack Mario, but if it shows its left eye, it is attacking Luigi. Then it would appear from behind, and charge towards one of the Mario Bros.. However, this could easily be countered with a jump. If the attack was not countered then the boo would steal an item which could only be recovered by defeating the boo. After a turn for each brother, the boo would [[Flee]] with the item. They also appear during the battle with [[Sunnycide]]. After the Mario Bros. flip the egg monster over, Sunnycide could summon a Boo to attack Mario or Luigi. [[Dark Boo]]s also return in the game, and are found in the [[Gritzy Caves]]. Also, when a [[Handfake]] has a [[Bowser]] sign, a Boo or a [[Fly Guy]] carries a flame from Bowser's mouth.

|A [[Bowser Memory Boo]].

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 players 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 [[Bowser Memory Boo|a square shaped, pixelated version of a 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.

While Boos themselves do not appear in ''[[Mario & Luigi: Dream Team]]'', an item named [[Boo Biscuit]] does.

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 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]]''.

 

A Boo appears in ''[[Mario vs. Donkey Kong]]'', acting similar to their other appearances in platforming games. They only appear in both segments of [[Level 4-4 (Mario vs. Donkey Kong)|Level 4-4]] and in [[Level 4-4+]]. They cannot be defeated, and if they manage to defeat [[Mario]] or the [[Mini Mario (toy)|Min-Mario]], the Boo will grow and stick its tongue out.

===''Mario Pinball Land''===

[[File:Bigboopinball.png|thumb|left|A group of Boos with [[Big Boo]] in ''Mario Pinball Land'']]

In ''[[Mario Pinball Land]]'', Boos appear in certain areas in the game. [[Mario]] cannot hit them at the front because they will become transparent as Mario passes through them. If Mario hits one of the Boos on its back, the Boo disappears and it is worth two-thousand points. They occasionally will disappear and reappear to another spot in the area.

A Big Boo also appears as one of the game's bosses. He is the boss of the haunted house and can only be damaged by hitting it from behind.

===''Yakuman DS''===

[[File:Opponent Selection Screen - Yakuman DS.png|thumb|A Boo on the opponent selection screen from ''Yakuman DS'']]

Boos appear in the Japan-only [[Nintendo DS]] game, ''[[Yakuman DS]]''. They are one of the many opponents. Other opponents include, [[Goomba]], [[Diddy Kong]], and [[Hammer Bro]]. Boos are not unlockable or playable. They are opponents from the start of the game.

===''Dance Dance Revolution: Mario Mix''===

[[File:DDRMMboos.jpg|thumb|left|A Boo with [[Mario]] from ''Dance Dance Revolution: Mario Mix'']]

Some Boos make appearances in ''[[Dance Dance Revolution: Mario Mix]]'' in both regular and giant varieties. Their objective is to try to make [[Mario]] miss a step. If successful, they block Mario's next move. Mario is able to step on regular Boos to hold them back, but he cannot do the same to their gigantic counterparts.

===''Mario Baseball'' series===

|align=left

|image1=Boo-Batting-MSS.png

|caption1=Boo prepares to bat in ''Mario Super Sluggers''

|image2=MSS Mini Boos Screenshot.png

|width2=160

|caption2=[[Mini Boo]] being used in ''Mario Super Sluggers''

Boo makes its first baseball appearance 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]]. Its chemistry with [[Luigi]], [[Yoshi]], [[Baby Mario]], and [[Baby Luigi]] is bad.

Also, a new item, called Mini Boos, appears. When activated, Mini Boos 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 effect, the Boos do nothing.

Boos appear in [[Princess Peach]]'s first starring game, ''[[Super Princess Peach]]''. They act as normal Boos, hiding their face when Peach looked, and attacking when Peach has her back turned. However, there is an angry variety called the [[Mad Boo]], which attacks the opposite way. They attack when Peach looks at them, and gander around for her when she looks away. Big Boos and their vibe counterparts, a new species called [[Mad Big Boo]]s, also appear.

 

King Boo also appears, as one of the bosses of the game. He will attack Peach by shooting fireballs at her, but she can use these to light the candles on the wall, damaging him. His vibe during the game is Gloom, which he will use to douse the candles.

[[File:MarioAndIncredibleRescue.jpg|thumb|120px|Two Boos on the cover of ''Mario and the Incredible Rescue'']]

Boos make an appearance in the chapter book ''[[Mario and the Incredible Rescue]]''. The cover features two Boos. One of the Boos is from ''[[Mario Kart: Super Circuit]]'' and the other is a mirrored Boo from ''[[Luigi's Mansion]]''. They are known as "ghosts" in the book. Boos capture [[Princess Peach]] and take her to [[Bowser's Castle]]. Mario also sees a vision of Princess Peach being caged and surrounded by six Boos. Boos are eventually defeated by Mario at the end of the book. To defeat them, Mario casts a spell on them and sends them flying out of the castle.

Boo makes an appearance in ''[[Mario Hoops 3-on-3]]''. It appears as an unlockable character. It is unlocked by beating the [[Flower Tourney]] on hard. Boo's special ability is the [[Thriller Dunk]]. This is performed by tapping a ''B''-like shape twice. In the game, the Boo is classified as a tricky character. The other tricky characters are [[Koopa Paratroopa|Paratroopa]], [[Fly Guy]], [[Black Mage]], and [[Moogle]]. Boo is also one of many of the unlockable characters to not have a baller name.

Although Boos do not appear in ''[[Super Mario Strikers]]'', they do appear in its sequel, ''[[Mario Strikers Charged]]''. Boos, along with [[Hammer Bro]]s., [[Toad (species)|Toads]], [[Koopa Troopa]]s, [[Birdo (species)|Birdos]], [[Dry Bones]], [[Monty Mole]]s, and [[Shy Guy]]s, are sidekicks to the many captains. They appear with a helmet with the logo of their team captain. Boos are classified as a playmaker. The only other playmaker sidekicks are Toads. Their skillshot is [[Possess]]. The given description of the Boos is: "''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.''" Boo's appearance in this game resembles that of the [[Spooky Speedster]].

[[File:BooMASATOG.png|frame|100px]]

====''Mario & Sonic at the Olympic Games''====

Boos are minor, supporting characters in both versions of ''Mario & Sonic at the Olympic Games''. They are not playable characters, but they can be seen in the crowd with other ''[[Mario (franchise)|Mario]]'' enemies, including [[Bullet Bill]]s, [[Goomba]]s, and [[Bob-omb]]s. A Boo will also appear to penalise the player if they perform two consecutive fouls in the [[100m (Mario & Sonic at the Olympic Games for DS)|100m]] event in the [[Nintendo DS]] [[Mario & Sonic at the Olympic Games (Nintendo DS)|version]], as well as blocking one of the baskets in the [[Dream Basketball]] event when a [[Chaos Emerald]] is used. In the [[Wii]] [[Mario & Sonic at the Olympic Games (Wii)|version]], Boos appear as an item in [[Dream Race (Mario & Sonic at the Olympic Games for Wii)|Dream Race]], where they will follow the character in first place, or second if the player is leading when they use the Boo, for a short amount of time and cause them to lose speed and remain at a low speed. Multiple Boos can follow a character at once, causing them to remain at a lower speed, and can be removed early by using a [[Power Sneakers|High Speed]] item.

 

====''Mario & Sonic at the Olympic Winter Games''====

In the [[Nintendo DS]] version of ''[[Mario & Sonic at the Olympic Winter Games (Nintendo DS)|Mario & Sonic at the Olympic Winter Games]]'', Boos appear as items in [[Ski Cross Racing]], where they can be used to steal [[Ring (Sonic the Hedgehog)|Rings]] and items from characters in front of the player. In [[Extreme Snowboarding]], Boos steal items from opponents in front of the player, as well as depleting the energy in their trick gauge. In [[Ski Shooting]], Boos will simply steal an item from an opponent if they have any when the item is used. King Boo also appears as a rival in both versions of the game.

 

[[File:M&S 2012 The Ghostly Tower.png|left|thumb|200px|King Boo talking to a Boo in [[The Ghostly Tower]]]]

Boos appear in the London Party mode of the Wii [[Mario & Sonic at the London 2012 Olympic Games (Wii)|version]] of ''Mario & Sonic at the London 2012 Olympic Games'', where they can be spoken to in order to play minigames and earn stickers, and also appear in some of the minigames as well. A jersey featuring a Boo design can be unlocked for [[Mii]]s to wear.

 

In the [[Nintendo 3DS]] [[Mario & Sonic at the London 2012 Olympic Games (Nintendo 3DS)|version]], 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 the Hedgehog|Sonic]] and [[Miles "Tails" Prower|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. 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, and they also referenced on Luigi and King Boo's badge descriptions.

====''Mario & Sonic at the Rio 2016 Olympic Games''====

Boos appear in [[Archery Plus]] in the Nintendo 3DS version of ''[[Mario & Sonic at the Rio 2016 Olympic Games (Nintendo 3DS)|Mario & Sonic at the Rio 2016 Olympic Games]]'', where they carry around the targets and disappear one they have been shot.

In ''[[Super Smash Bros. Melee]]'', Boo appears as a collectible trophy.

 

[[File:BrawlTrophy169.png|thumb|100px|left|The trophy of a Boo from ''Super Smash Bros. Brawl'']]

As well as appearing as a [[Trophy (Super Smash Bros. series)|trophy]] in ''[[Super Smash Bros. Brawl]]'', Boos make cameos in the [[Luigi's Mansion (stage)|Luigi's Mansion stage]]. When a part of the mansion is knocked down, Boos are seen flying out. Boo from ''Mario Tennis'' also appears as a collectible [[Sticker (Super Smash Bros. Brawl)#Boo|sticker]].

 

Boo appears in the form of a collectible trophy in ''[[Super Smash Bros. for Nintendo 3DS]]'' and ''[[Super Smash Bros. for Wii U]]''. In the latter, Boos return in the Luigi's Mansion stage from ''Super Smash Bros. Brawl'', and they appear as [[smashwiki:Smash Tour|Smash Tour]] items: when used, the player starts a battle invincible.

 

Boos are seen again in the returning Luigi's Mansion stage. A Boo appears in ''[[Super Smash Bros. Ultimate]]'' as a Novice-class Neutral-type primary [[Spirit (Super Smash Bros. Ultimate)|spirit]], using the artwork from ''[[New Super Mario Bros. U]]''. In [[Super Smash Bros. Ultimate#Adventure|World of Light]], it is found in the Dracula's Castle sub-world of the Dark Realm. The spirit battle takes place on the [[Mushroom Kingdom U]] stage, with an invisible grayscale [[Kirby]] as the puppet fighter. The spirit can be enhanced to a [[King Boo]] spirit at level 99.

Boos appear in ''[[Mario Sports Mix]]''. They appear as the only members of the crowd in [[Luigi's Mansion (place)#Mario Sports Mix|Luigi's Mansion]] circling around the court. Their appearances are in [[Mario Sports Mix#Basketball|Basketball]] and [[Mario Sports Mix#Volleyball|Volleyball]] matches and their laughs can also be heard during the game. Mainly, they can be heard when the player gets a point.

[[File:Boo_CTTT.png|150px|thumb|left|A Boo in ''[[Captain Toad: Treasure Tracker]]'']]

Boos return in ''[[Captain Toad: Treasure Tracker]]'', functioning the same as they did in ''Super Mario 3D World'' with a few minor tweaks. Despite still chasing the player when not watched, Boos and [[Big Boo]]s can easily be destroyed with Toad's or Toadette's headlamp. Additionally, using a [[Double Cherry]] to shine two headlamps on a Boo will defeat it much faster, within a quarter of a second.

 

Interacting with Boos on the touch screen or with the pointer functionality will cause them to disappear until the player points away. Unlike most enemies in the game, holding the pointer on Boos for however long will not reward a coin.

[[File:Card SuperRare Boo.png|thumb|A Super Rare Boo card from ''Mario Sports Superstars'']]