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King Boo is the leader and king of the Boos, the ruler of the Paranormal Dimension, the archnemesis of Luigi, and the main antagonist of the Luigi's Mansion series. He is sinister, clever, and determined in the Luigi's Mansion series. He is considered the arch-nemesis of Luigi and was seen in the beginning of Luigi's Mansion where he ended up trapping Mario in a painting. His powers include causing objects to appear out of and disappear into thin air, and control over fire, ice, and lightning attacks. King Boo consists to be the main antagonist in most Mario series.

King Boo also appears in Mario Kart: Double Dash!! and Mario Kart Wii as an unlockable racer. In Double Dash!!, King Boo teams up with Petey Piranha. His last spin-off appearance so far shows him in Mario Kart 8, but only in the game's Switch version. His design in these games is somewhat cuter, but still somewhat terrifying.


Personality traits

King Boo is shown to harbor a deep hatred for the Mario Bros. He claims this is due to the trouble the duo has caused him in the past, presumably referring to all the Boos the Mario Bros. had defeated, as King Boo had not been in any games prior to Luigi's Mansion. His hatred grows towards them in later games, especially Luigi after the latter defeats him in Luigi's Mansion and subsequent sequels. This grudge towards Luigi is reflected in his interactions with the plumber, such as when he childishly insults him in the Luigi's Mansion games and insists on racing against him in Mario & Sonic at the Olympic Winter Games, fully aware of how afraid Luigi is of ghosts.

He says that he fears nothing except the Poltergust 3000, although in Super Mario 64 DS he also admits that Wario's face scares him. In the Mario and Sonic series, he has a superiority complex and is quite prideful. In Mario & Sonic at the Olympic Winter Games, he claims that he is unbeatable at the Alpine Skiing event. In Mario & Sonic at the London 2012 Olympic Games, he claims to have beaten Mario before.

King Boo loves to scare and toy with his opponents, rather than defeating them quickly. In Luigi's Mansion, he chooses to use his powers to blow Luigi back to the foyer instead of trying to finish him off while at maximum power, and enjoys watching Mario struggle from within the painting he was trapped in, stating Mario's desperate attempts to break free were "satisfying."

Despite his huge size and immense power, he still covers his face in fear when looked at, much like a normal Boo, showing that he still has a shy nature like his minions; however, also like a normal Boo, he attacks when his foe's back is turned. King Boo has a distinct cackle, which is significantly lower in pitch than other Boos. He also has an echo in his roar.

King Boo usually considers his Boo minions as friends and cares for them. This is shown in Luigi's Mansion where he goes to free Boolossus after he is captured by Professor E. Gadd, and when he threatens to hurt Paper Mario if the Mario Brothers dared to hurt his Paper Boo minion in Mario & Luigi: Paper Jam. He also has good chemistry with the playable Boo in the Mario Baseball series. In Mario Super Sluggers, King Boo says that he finds little Boos cute.

After breaking out of the portrait he was placed in at the end of Luigi's Mansion, he displays a complete disregard for anything that interferes with his revenge against the Mario Bros. and displays several sociopathic traits, including a disregard for others' well being, and at one point nearly causing the world itself to collapse. Additionally, he no longer cares about his Boo minions, as not only does he not show much concern for them in Luigi's Mansion: Dark Moon, but he even indirectly calls them useless in Luigi's Mansion 3. He does not seem to care for ghosts that are not Boos, instead using them in his plans as tools rather than subjects. Even Hellen Gravely, a ghost who adores him, is seen as nothing more than a pawn or, at best, someone to whom he is indifferent. Professor E. Gadd comments on how King Boo had redecorated the Treacherous Mansion to make it scarier. He also goes into fits of rage when his plans do not go the way he wants. In Luigi's Mansion: Dark Moon, King Boo also has a bit of a sarcastic demeanor as well, as when formally revealing himself to Luigi before fighting him, he references his previous defeat at the hands of Luigi as "Good times", despite clearly being angry and vengeful over it. In Luigi's Mansion 3, King Boo impersonates Mario and Luigi's Italian accent saying, "It's-a me, King Boo!" and uses false comfort towards Luigi. Also in said game, he is shown to have a degree of cunning, as it is strongly implied that he deliberately had Hellen Gravely guard only Mario's portrait in anticipation of Luigi defeating her, and that he could then use Princess Peach's portrait as bait to draw out the Mario Brothers in order to recapture all the portraits, with him very nearly succeeding in this endeavor.

Powers and abilities

  • Invisibility: King Boo being king of the boos can turn invisible; however being a boo master it can use the most compelling powers of invisibility.
  • Boo Call: King Boo can use his crown to call more Boos.
  • Slot Machine: only seen in Super Mario Sunshine, King Boo can use a slot machine to determine what items Mario can get.
  • Portal: King Boo can also create portals to escape to other dimensions.
  • ground pound: king boo hits the ground causing shock waves often sending Luigi flying.

Super Mario series

Super Mario Sunshine

King Boo's appearance in Super Mario Sunshine.

King Boo returns in Super Mario Sunshine, in which he is the boss of episode five of Sirena Beach. To reach him, Mario must head to the casino of Hotel Delfino and Ground Pound a purple platform, which is later sent to the bottom level. At the bottom level, King Boo appears after he does a creepy laugh and his wheel will start to rotate; ground pounding the purple platforms will stop one section of the wheel. Mario must defeat him by tossing peppers into his mouth (after a slot result gives Mario fruit) and then tossing another fruit into the mouth as King Boo tries to recover. Doing this three times earns Mario a Shine Sprite. In Super Mario Sunshine, however, instead of being a Boo with a crown and sharper teeth, he is wider, fatter, and drooling, but still retains his crown.

This may be because Bowser Jr. painted him, and he doesn't like King Boo stealing Bowser's thunder as big bad boss o' Mario, which is further backed up by the fact that he turns invisible in Super Mario Sluggers to hide from Bowser Jr.

Super Mario 64 DS

King Boo follows Mario.

In Super Mario 64 DS, Mario must defeat King Boo to save Luigi, and unlock him in gameplay. Luigi is an optional character who is required to collect all 150 Power Stars. Mistakenly, in his Super Mario 64 DS appearance, King Boo was called Big Boo, even though the actual Big Boo was a 2-time boss at his own haunt. This is corrected when he and the other Super Mario 64 (DS) bosses return in Mario Kart DS. King Boo does not appear in the Nintendo 64 console version of the game due to the fact that he didn't exist when the original game came out.

Mario Sport series

Mario Superstar Baseball

In Mario Superstar Baseball, King Boo is a minor playable character in the power category who is on Wario's team in adventure mode and is a starter character. He bats and pitches are right-handed.

Mario Super Sluggers

King Boo's artwork from Mario Super Sluggers

King Boo appears as a playable character. He spectated the game at Wario City, turning invisible to not be seen by Bowser Jr. In story mode, King Boo will refuse to join your team unless a Boo is on it. He also gives the hints which are "error item" and "in a box." he has good chemstry with Petey Piranha King K. Rool Wiggler and Boo while having bad chemistry with Luigi.

Mario Kart series

Mario Kart: Double Dash!!

King Boo as he appears in Mario Kart: Double Dash!!

In Mario Kart: Double Dash!!, King Boo is a hidden character who is unlocked after the player finishes the Star Cup on Mirror Mode alongside his partner Petey Piranha, making him one of the toughest characters to unlock. King Boo is paired with Petey Piranha and, like his partner, is a heavyweight. However, his kart (the Boo Pipes) is a heavy kart with the speed of a lightweight kart. Just like the Boss Pakkun himself, he can also use any Special Item.

Mario Kart DS

King Boo as seen in Mario Kart DS.

In Mario Kart DS, King Boo is a boss in the fourth level mission mode, the playable character is Peach. His stage is a lava arena. Here, the player has to collect fifty coins from him. When he takes them, the player must try to get them when he is teleporting and continue collecting coins.

Mario Kart Wii

King Boo as he appears in Mario Kart Wii.

In Mario Kart Wii, King Boo is a heavyweight hidden character who can be unlocked after the player finishes the Star Cup on 50cc or if the player plays a total of 750 races.

Despite being an excellent handler, King Boo is a mid-tier character for his poor raising stats. King Boo is a good choice for courses with tight turns, such as Rainbow Road. Despite his mid-tier placing, King Boo has great rivalries with other characters and has excellent racing skills, making him a character with high-tier or possibly top-tier character categories since his handling stat raises any kart or bike, including the Spear.

Mario Kart 8 Deluxe

King Boo returns to Mario Kart 8 Deluxe as a new playable character along with Bowser Jr., Dry Bones, Inkling Girl, Inkling Boy, and Gold Mario. He is controlled by the 200cc staff ghost, Nin★Rui (from Portugal) on a Wild Wiggler with Sponge tires and Flower Glider with the time of 1:38.244 for Twisted Mansion.

King Boo does not appear in the original Wii U version of Mario Kart 8.

Mario Kart Tour

King Boo returns in this new installment of the Mario Kart franchise. He appears two times: 1. As his normal self 2. As his Luigi's Mansion counterpart (as a highlight). The first King Boos special item is the Lucky Seven, the second King Boos special item the Bob-Omb Cannon. Both of them are relatively hard to unlock, considering the 1. King Boo is a rare driver and the 2. King Boo a high-end (spotlight) driver.

Mario Party series

Mario Party 8

King Boo is the host of his own board entitled King Boo's Haunted Hideaway in Mario Party 8. He'll force the players to traverse through his rearranging mansion and find him at one of three altars (the other two being traps). If a player does manage to find him, the player can buy a Star for ten coins. He would then send all the players out and rearrange the mansion. King Boo does not rearrange his mansion upon meeting him in the Star Battle Arena, making his room easier to find the second time.

The player could also buy King Boo's sounds and a figurine titled "King Boo's Revenge."

Mario Party 9

King Boo appears to be the third stage boss in Boo's Horror Castle with his own boss minigame, King Boo's Puzzle Attack. He will send out Boos to attack the players as they shift the powerups to match and attack him. After his health drops to half and he turns furious, King Boo will use two instead of one.

Luigi's Mansion series

Luigi's Mansion

King Boo in Luigi's Mansion

In Luigi's Mansion, King Boo makes a haunted mansion and sends a letter to the Mario Bros, stating that Luigi won a grand mansion in a contest(that Luigi never attended). About the same time, he releases all the portrait ghosts Professor E.Gadd has caught before and later catches Mario(who went to the mansion himself and traps him in a painting. Luigi, in the meantime, has no clue that the mansion is haunted, or that Mario is kidnapped. Later, after encountering a group of ghosts, Luigi meets the Professor who gives him the Poltergust 3000 and tells Luigi how the Boos freed all of his Portrait Ghosts. Luigi then sets off to save Mario, but later on, he ends up in a storage room and frees all fifty Boos, as well as King Boo himself; Luigi then obtains a Boo Radar for his Game Boy Horror. Halfway through his quest, Luigi discovers where King Boo has been keeping Mario and sets off to find the key to his room.

King Boo comes out of Bowser's body.

At the final battle, King Boo pilots a giant Bowser mecha (intricately made to look just like Bowser, although a false Bowser) to help him battle Luigi. The player must defeat him by tossing a spike ball at the Bowser robot's head and then sucking up King Boo like a regular Boo. Afterwards, King Boo is defeated, Mario is rescued, and King Boo ends up in a portrait with the fake Bowser suit. He has the exact same role in the game's remake.

Luigi's Mansion: Dark Moon

King Boo's artwork from Luigi's Mansion: Dark Moon

King Boo returns as the main antagonist of Luigi's Mansion: Dark Moon. He is seen destroying the Dark Moon in the opening cutscene, causing all the ghosts of Evershade Valley to lose control and run rampant throughout the mansions located there. Though he does not reveal himself to Professor E. Gadd and Luigi at first, numerous Boos are seen throughout the game, and the king himself makes several cameos before his grand appearance, all of which are short, subtle, and with his back turned. In several security camera images seen in the game, Boos are seen carrying a sack with an odd portrait of what appears to be a person. When Luigi gets to the last mansion, the Treacherous Mansion, he shines his light into the dark entrance. When he sees nothing, he turns around and looks for anything that may be behind him. After he turns around, King Boo appears and grins at him menacingly.

Once Luigi rescues the two Toad Curators from the Treacherous Mansion, the final security image reveals that the painting being carried around is in fact Mario, who has been once again imprisoned by King Boo. King Boo, also in the image with his back turned, suddenly turns around and reveals himself to E. Gadd and Luigi, and causes the lab's screen to go fuzzy. Luigi goes into the Mansion's train exhibit to ambush the king, only to be attacked by a Big Boo made of ten smaller Boos that Luigi shoots to the train.

Luigi defeats Big Boo, and then the Tough Possessor to nab the final piece of the Dark Moon. However, before he can return to the lab, Luigi's Pixelation is intercepted by King Boo, and Luigi is sucked into his illusion. There, King Boo taunts Luigi and confesses that he destroyed the Dark Moon and trapped Mario in a painting so he could seek revenge on Luigi(and E. Gadd) and become ruler of the world. An intense battle ensues and ends with King Boo being once again trapped in the Poltergust 5000 and Luigi stealing the ruby atop his crown.

Oddly enough, King Boo is not seen in the Boo Vault after the game's completion. However, he can be re-fought as many times as the player would like in the level of King Boo's Illusion.

Though it is not officially revealed how King Boo escaped his painting, E. Gadd notes that he "shouldn't have sold it at a garage sale," implying that there may have been some external force helping to free King Boo.

To defeat him, make him slam the floor, making spike balls summoned earlier into the air and make him stay in the spots where the balls will drop. This will stun him before Luigi is able to start vacuuming.

Luigi's Mansion 3

King Boo reappears in Luigi's Mansion 3 with the same design as in Luigi's Mansion: Dark Moon. King Boo, having been released by Hellen Gravely, the owner of the hotel and a big fan of his, in order to impress him. Seeking revenge on Luigi for his previous defeats, he traps Professor E. Gadd, Mario, Princess Peach, and the three Toads in portraits before going after Luigi, who manages to escape his capture by going down a laundry chute.

He later ends up entrusting Hellen Gravely with Mario's portrait, although it's implied that he intended for Luigi to win both due to Gravely's failures by that time and so he could capture both alongside Peach by using the latter as bait, also recapturing the Toads and Professor E. Gadd just after Mario was freed. However, he ultimately fails to capture Luigi atop the hotel due to Polterpup shoving him out of the way of King Boo's portrait, and then proceeds to battle Luigi.

To defeat King Boo, Luigi must throw a bomb from a spiked ball King Boo throws into his mouth, then pull on his tongue with Gooigi's help and slam him repeatedly. Upon doing so, King Boo will then generate a clone that attacks alongside him. After this is done twice, King Boo will enlarge the painting, and Luigi will then have four minutes to attack King Boo one last time. The battle ends with King Boo being recaptured by Luigi and placed in a containment jar alongside Gravely, much to his chagrin. As the purple gem in his crown was taken by Luigi after the final battle, it is missing from his crown.

If the player gets a game over at any point during this game, King Boo will be shown trapping Luigi in a portrait alongside the rest of his friends.

King Boo trapped everyone except Luigi.

Other appearances

Super Princess Peach

King Boo appears in Shriek Mansion. However, the lanterns go out. As a result, the Toad will fade with the bubble and the three Boos. King Boo suddenly becomes less transparent and the crown lands on his head.

King Boo has few starting attacks: floating towards Peach and send blue fireballs. To attack him, Peach should use the Rage vibe to lighten up the four lanterns. As a result, King Boo will disappear and his crown falls to the ground. He reverses the lanterns off and continues the battle.

When he has a low life, he cries with many tears to extinguish the lanterns.

After finishing him off, he enlarges, disappears and his crown explodes. This rewards her the kidnapped Toad.

Mario & Luigi: Paper Jam

King Boo is seen at Gloomy Woods during the second visit where he has taken control over the forest. King Boo makes his presence known where Mario, Luigi, and Paper Mario inspect an odd tree. Luigi runs off scared but when he returns seconds later, it is shown King Boo has captured Mario and Paper Mario forcing Luigi to look for them alone. Mario and Luigi eventually reunite and find Paper Mario on the other side. However, it turns out to be King Boo in disguise and then fights them in battle.


  • One of King Boo's lines from Luigi's Mansion is a reference to Star Wars: Return of the Jedi "I will not give up on my favorite decoration. I like Mario just where he is" He says this if you confront him before the end of the game.
  • Interestingly, King Boo is one of the Heavyweight characters, despite being a floating, weightless ghost. This may be due to the weight of his crown or his large size.
  • He usually uses his tongue to mark which direction he is going. This can be useful if you're lost.
  • King Boo is the only character in Mario Kart Double Dash!! to not yell or say anything when being shot from the cannon in DK Mountain. (Though in Mario Kart Wii, he does.)
  • When the player drives behind him and a blue wave appears, he doesn't turn his head to look behind him like all the other characters. This is probably because he already knows that you're behind him, or turning his "head" to look behind him will result in turning his whole body.
  • In Luigi’s Mansion 3, during the final battle, the clones that King Boo summons in the final battle reference his original design from Luigi's Mansion, as they only have two teeth, lacking the middle two fangs King Boo is depicted with now.
  • The crown from Dark Moon may be a variation off of his original crown, mixed with the Dark Moon shard preventing it from being a full moon.
  • This is further backed up by his eyes being shaded purple and the area around them being shadowed.
  • His Luigi's Mansion counterpart along with Dimentio are the only two Mario villains to be Pure Evil/Complete Monsters.



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