King Boo/Synopsis

The story of the tyrannical King Boo from the Mario franchise.

Luigi's Mansion
King Boo made his first major appearance in the game Luigi's Mansion. He is angry with the Mario Brothers for causing the Boos so much trouble in the past, so he designs a plot to get rid of them both. He sends Luigi a note telling him he has won a mansion in a contest that he did not enter. Luigi calls Mario and tells him the good news, asking him to go there and meet him so they can celebrate. Mario goes to the mansion to investigate, but King Boo captures him. However, when Luigi arrives, Mario is nowhere to be seen, and the mansion is infested with ghosts.

Later in the game, Luigi finds King Boo staring at a painting with Mario trapped inside. Also, he finds out that King Boo was the one who created the mansion and released all the ghosts within it. At the end of the game, Luigi fights what appears to be Bowser, who is apparently revived by King Boo after his (unseen) previous defeat. However, it is then shown to be really King Boo in what seems to be a Bowser costume. Luigi defeats King Boo and sucks him into the Poltergust, and later turns him into a portrait with the Portrificationizer. Then, Mario is freed from his painting and Luigi becomes glad that Mario is okay.

Luigi's Mansion: Dark Moon
King Boo reappears in the sequel to Luigi's Mansion on the 3DS and seeks revenge against Luigi for his imprisonment. At some point in this canon, E. Gadd sold the painting at a yard sale. King Boo initiates the events of the game by destroying the Dark Moon, a purple crescent-shaped artifact that keeps the ghosts of Evershade Valley in a docile state. Shattering the Dark Moon into pieces, King Boo incites the ghosts to turn on E. Gadd which leads to his summoning of Luigi for help.

Though the course of the game, the true extent of King Boo's plans are revealed: to mine special gems similar to the one on his crown so he can increase the power of Evershade Valley's now-hostile ghosts and build an vast spectral army of them to conquer the world.

After Luigi successfully obtains all the Dark Moon Pieces, King Boo intercepts his teleportation back to E. Gadd's Bunker and entraps Luigi in an alternate dimension. There, King Boo appears in front of Luigi after revealing he had again trapped his brother Mario inside a painting. King Boo then taunts Luigi before announcing his intent to turn all his foes into paintings. A battle ensues between them which ends with Luigi triumphant, although after catching King Boo in the Poltergust 5000, no specific mentions of King Boo's fate is ever brought up. Luigi then frees Mario once again freed from a painting and the Dark Moon is repaired, restoring all of the ghosts of Evershare Valley to their friendlier states and Luigi is declared a hero.

Luigi's Mansion 3
In Luigi's Mansion 3, sometime following his defeat in Dark Moon, King Boo is revealed top have been kept imprisoned by E. Gadd. However, E. Gadd is later lured to The Last Resort hotel by its owner Hellen Gravely, who subsequently frees him and all the other ghosts Luigi had previously captured before imprisoning Gadd in a portrait. Wanting to impress King Boo, Gravely begins to plot with him to lure Luigi and his friends to her hotel to be trapped. Their plan ends up succeeding, and King Boo manages to trap Mario, Princess Peach and three Toads in portraits. When Luigi investigates their disappearances, he comes across Gravely, who reveals her true nature and admiration for King Boo before he presents himself. He proceeds to taunt Luigi about his escape and plan, revealing all of his trapped friends before sending their portraits away and preparing to trap Luigi as well. King Boo chases after Luigi down the hall, although he runs away and manages to escape using the laundry chute, subsequently finding E. Gadd's new Poultergust G-00 and rescuing him from his imprisonment.

King Boo later appears after Luigi defeats Captain Fishhook and rescues the final Toad, where Gravelly begs to be given more time to capture Luigi for him, although, seemingly disinterested in her plans, he takes Princess Peach's portrait and leaves her. Once Luigi reaches floor 15, Gravely decides that it is a good thing that he made it so far as she now has the opportunity to personally capture him and impress King Boo, and prompts him to come after her by revealing Mario's painting in her possession. Once Luigi finally confronts Gravely, she lashes out at him for ruining her plans by cowardly running away from King Boo and making her lose his approval, resolving to defeat him herself, although she is ultimately captured instead. Afterwards, upon freeing Mario, Luigi heads to the top of the hotel with him to find and rescue Princess Peach, only for King Boo to arrive once they have reunited. After expressing his rage towards Gravely and her ghosts for failing him, he declares to the heroes that he is going to trap them in an ensemble portrait once and for all; summoning and destroying E. Gadd's portable lab to trap him and the Toads before capturing Mario and Princess Peach, with Polterpup narrowly preventing Luigi from being trapped as well.

Furious over Luigi escaping his trap, King Boo decides to engage him, leading into their final battle. Upon being overcome by Luigi and Gooigi twice, King Boo uses his magic to enlarge the portrait until it is big enough to encompass the entire hotel, forcing Luigi to have to defeat him before everything is swallowed up. Ultimately, Luigi is able to suck up King Boo by his tongue and trap him, releasing his crown's gem in the process, leaving the hotel to crumble before he is able to release his friends. Following this, the captured ghosts suddenly escape from their imprisonment and begin to swarm Luigi until King Boo's gem disappears (suggesting that he had been using his powers to control them). During the credits, Luigi and his friends rebuild the hotel alongside the ghosts, while King Boo is shown to be trapped again with an affectionate Gravely and Polterkitty nearby, much to his dismay.

Super Mario Sunshine
A Boo with the same name as King Boo appears in Super Mario Sunshine, where he fought Mario at the casino of Sirena Beach. He uses a slot machine in battle, and Mario defeats him by throwing spicy peppers at his tongue, setting it on fire, and then throwing fruits at him. After three hits, King Boo is defeated.

It's theorized that this Boo is not the actual King Boo and several evidence are given: its name in the Japanese name translates as "Boss Boo" (which King Boo himself has never been called); its crude appearance and death by dissolving into goop suggests it's actually a painting made by Bowser Jr.'s Magic Paintbrush; lastly, Sunshine (in a rather rare case where Mario games have confirmed chronologically) takes place after the events of the first Luigi's Mansion, which explains Luigi's absence.

Super Mario 64 DS
King Boo also makes an appearance as a boss character in the DS remake of Super Mario 64. King Boo aids Bowser with taking over Peach's castle. He also managed to kidnap Luigi. Mario had to venture into Big Boo's Haunt and locate a picture of Luigi. Once he found and entered the picture, Mario finds himself in a world where King Boo is. He taunts Mario thinking that he'll never find his brother. However, by listening to King Boo's laughter, Mario was able to locate to where King Boo was hiding. When he entered the room where King Boo was hiding, Mario spots a large mirror. Eventually, King Boo arrived and confronted Mario. Mario had to use the mirror to locate King Boo, and stomp on King Boo several times. Eventually, Mario managed to defeat King Boo, and rescue Luigi.

Super Princess Peach
However, King Boo is revived by Bowser at least once more, and appears as the third boss in Super Princess Peach, at Shriek Mansion. He is shown to have a weakness for extremely bright lights, as when Peach uses Rage to light all the torches in the room, King Boo takes damage. Once this happens five times, King Boo is destroyed.

Mario Kart
King Boo also appears in spin-offs such as Mario Kart: Double Dash!, in which he is an unlockable and playable character. He also appears as playable character in other Mario Kart games including Mario Kart Wii and Mario Kart 8 Deluxe. He also appears as a boss character in Mario Kart DS and makes a cameo in Mario Kart Arcade GP 2.

Mario Baseball Series
King boo also appears as an enemy/playable character in the Mario Baseball series.

King Boo is a playable character in Mario Superstar Baseball and a member of Wario's baseball team called the Wario Greats. He does not need to be unlocked. He is a power hitter, using his white, crowned, Boo-like baseball bat to hit long outfield drives and even homeruns. King Boo has chemistry with Boo and Petey Piranha, and he has bad chemistry with Luigi. However, like Boo, his hits are usually very curved, and this causes them to be fouls most of the time.

King Boo reappears in Mario Super Sluggers and he is one of the few characters that were on Wario's team in the last game that are still on it. He is once again a power hitter, and he also excels in pitching, with both stats being his highest. In Challenge Mode, he appears immediately after the player defeats Bowser Jr. at the Wario City stadium, stating that he turned invisible and was watching the whole game. However, he is uninterested in joining the player's team unless the team has some Boos with them. This is accomplished by finding both Boo and the Mini Boos item. In this game, King Boo has chemistry with Petey Piranha, Boo, King K. Rool, and Wiggler, but he has bad chemistry with Mario, Luigi, Baby Mario, and Baby Luigi.

His baseball bat does not have a physical crown on it anymore. In this game, it is represented as a crown picture above the "Boo mouth" picture. As well, in this game only the colours of the jewels on his crown are reversed.

Mario Party Series
King Boo also made appearance in three Mario Party games. All of which, appears as an enemy towards the players.

Mario Party 8
King Boo makes his first appearance in a Mario Party game in Mario Party 8. He gives out Stars on his own course, King Boo's Haunted Hideaway. He hides in one out of three altars and gives the player a Star for ten coins if they can find him where he is hiding. If the player is able to buy the Star, he will "summon the bizarre" and disappear, causing the player to jump into a Warp Pipe that returns them to the starting point. This "makeover mojo" causes the whole layout of the course to change. However, if they do not have enough coins, King Boo will cause a pitfall to appear under the player, causing them to return to the starting point and allowing the next player that reaches him to buy the Star. Additionally, if the player fails to steal anything from the board event Pickpocket Pinball, the hosting mouse sounds like King Boo. The player can purchase King Boo sounds from the Fun Bazaar, along with a figurine titled "King Boo's Revenge". When the player presses A Button on the figurine during the Figurine Parade, King Boo floats up and gives off a brilliant glow, as if he is a light bulb.

Mario Party 9
King Boo appears as the stage boss of the board Boo's Horror Castle in Mario Party 9. He is fought in the minigame, King Boo's Puzzle Attack, where the competitors line up power-ups in lines of three or more to deal damage to him. Once his health reaches halfway, he throws Boos onto the field which can stun the player's cursors, making them unable to move until they shake the Boo off. What is unique about his boss battle is that if a player gets the Final Attack, they get ten points instead of the usual three, likely because the players can easily accumulate points up to fifty. In the final fight against Bowser, King Boo can also appear to hinder the players' progress. If Bowser throws the die with all the stage bosses' faces on it and King Boo's face appears on top, King Boo will materialize above the stage. Then, he will summon five Boos that move in a counterclockwise direction while moving outwards. When the Boos reach the boundaries of the stage, King Boo summons another five Boos, except this time they move clockwise. After that, King Boo disappears from the battle unless his face appears on the top of the die again. King Boo also has a constellation that can be returned to the sky; it is called the Ghost Major. It is located in the farthest left portion of the sky, near Big Bob-omb's constellation and right next to Boo's constellation. Like all constellations, it can be bought for fifty Minigame Points.

Mario Party 10
King Boo reappears in Mario Party 10. He returns as a boss in the minigame King Boo's Tricky Tiles. In order to defeat him, the player must remember which platforms are false, and then run around until they can jump on a light switch (one is worth 3 points, and another worth 1 point). Like other bosses, King Boo will get angered after the players deplete his health halfway. The technique that King Boo uses is that he swaps Boos with platforms and he blocks the camera, so the player cannot see the platforms very well and remember which ones are false. He can also be seen on the Luigi Board, which appears in the game's amiibo Party mode.

Mario & Sonic Olympic Games series
King Boo also made appearances in most of the Mario & Sonic Olympic Games series.

Mario & Sonic at the Olympic Winter Games
In the Wii version of Mario & Sonic at the Olympic Winter Games, King Boo appears as the first and sixth (in Individual Festival mode only) rival. King Boo races the player in the Alpine Skiing Downhill event in both Individual and Group Festival modes but he only races the player in Giant Slalom in the Individual Festival mode. King Boo has no skis so he goes down the hill smoothly. If the player loses to him, the guide (either Cream or Toad) says that it is unfair because King Boo has no skis.

In the Adventure Tours mode in the DS version, King Boo is the mid-boss of Polastraits. When the challenger approaches him, King Boo tells Mario/Sonic that he must race someone afraid of him. He selects Luigi and they must race in Giant Slalom. In this version, King Boo is transparent and the player can ski through him. He also appears slightly larger than in his other appearances.

Mario & Sonic at the London 2012 Olympic Games
King Boo appears in the next installment of the Mario & Sonic series, Mario & Sonic at the London 2012 Olympic Games. In the Wii version, he is one of the characters that can be found in the London Party mode, and when he is encountered, he will challenge the player to the Dream Sprint event. Since he has no feet, though, it is questionable how he gets the ball to roll. If the player reaches the goal line before him, they will get a sticker as an award.

In the 3DS version, King Boo teams up with a Boo to face Sonic and Tails in the Badminton Doubles event. After winning, the player completes Sonic's second episode.

Mario & Sonic at the Sochi 2014 Olympic Winter Games
King Boo appears in Mario & Sonic at the Sochi 2014 Olympic Winter Games as a rival in the Legends Showdown mode. He is found in Area 4, and is raced against in Short Track Speed Skating 1000m.

Mario Golf: World Tour
King Boo makes a cameo appearance in Mario Golf: World Tour on Hole 4 of Bowser's Castle. He is floating in the background alongside other Boos, and he is also much larger than in other games. His name can also appear on the tournament scoreboard.

Mario & Luigi: Paper Jam
King Boo makes his Mario & Luigi debut in Mario & Luigi: Paper Jam as a boss in Gloomy Woods. After the Mario Bros. are separated, King Boo kidnaps both Mario and Paper Mario, leaving Luigi to find them. After finding Mario, he and Luigi find Paper Mario, only for it to be a disguised King Boo. He toys with the Mario Bros. by reverting to Paper Mario when they look at him, but they are not fooled, causing the battle to commence.

During the battle, King Boo calls a Paper Boo holding the real Paper Mario, threatening to hit him if he is attacked. Mario and Luigi must defeat the minion holding Paper Mario instead of attacking King Boo, as he will attack Paper Mario. Eventually, another Paper Boo will capture Paper Mario, and the same rules apply. After King Boo is defeated, the trio continues on their way to Mount Brr.

Prior to fighting King Boo, a Papercraft King Boo is fought in Bowser's Castle piloted by Morton Koopa Jr. and Lemmy Koopa.

Super Smash Bros.
King Boo appears in Super Smash Bros. for 3DS as an unlockable trophy. In Super Smash Bros. Ultimate, King Boo appears as a Neutral type Primary Spirit, available by enhancing the Boo Spirit. When equipped, he slows the Fighter's falling speed after jumping.