Hey, remember when you trapped me in a painting for all eternity? Good times. But guess what? I GOT OUT! And now I'm painting the town red!
~ King Boo to Luigi.

King Boo is the main antagonist of the Luigi's Mansion sub-series. King Boo is a large Boo with magenta eyes (red eyes in the original), an indigo tongue, and wears a ruby-like crown.

He retains his position as the absolute ruler of the Boos, but he sometimes works independent from Bowser and is notably much more evil than how he was in the main series.

He was voiced by Kazumi Totaka, who also played Professor E. Gadd and Yoshi.


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 didn't enter. Luigi calls Mario and tells him the good news, asking him to go there and meet him so they can celebrate. 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.

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 same 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.

Eventually, King Boo reveals himself to Luigi after intercepting E. Gadd's teleportation and entraps Luigi in an alternate dimension. There, King Boo demands the Dark Moon pieces from Luigi so that he may conquer the Mushroom Kingdom with a spectral army in exchange for releasing Mario, once again trapped in a painting. Luigi naturally refuses and the battle ensues, with Luigi triumphant. However, after catching King Boo in the Poltergust 5000, no specific mention of King Boo's fate is ever brought up.


This version of King Boo is notably darker than the main series version. King Boo initially was much more fair in his rule, going out of his way to save a high-ranking Boo and generally acting fond of his own troops. He despised the Mario Brothers, and so plotted to get rid of them by capturing Mario and then tricking Luigi, so he could store them both into paintings. He also hates Professor E. Gadd for similar reasons, his Poltergust the only thing he fears.

In the sequel, all King Boo's altruistic traits have been rendered null. King Boo, after his first defeat, started to loathe Luigi even more than E. Gadd and Mario, to the point of conducting an elaborate revenge scheme involving shattering the Dark Moon and causing the benevolent ghosts to fly out of control. King Boo is consumed by revenge, and notably cares little for his troops, experimenting on the ghosts he enslaved and broke into submission and treating his Boos as common casualties. It reaches the point where King Boo willingly opens a portal to the ghost's home world with the intent to destroy the universe as an act of spite. King Boo is noticeably less comedic and more openly cruel to Luigi, as well as sadistic, clearly relishing the terrified Luigi's pain with his mind games.


Many fans speculated due to Bowser Robot that King Boo used in his first battle against Luigi, as comparing to the other mechs in the Mario universe, this one looks quite realistic. As the Mario universe has no set timeline, fans say that it is possible for Bowser to get killed and King Boo inhabiting his corpse. As the last game before King's debut was Paper Mario set in Japan as Mario Story, people say that one of the ghost in the first mansion is reading Mario Story, which can be historical book. Also, fortune-teller in the mansion exclaimed that King Boo could possibly revive Bowser, which means that King Koopa was already dead. There are several visions of the situation:

  • King Boo revives Bowser and takes his place as Koopa King, so in future games Bowser is gain supernatural abilities to stay alive even when burned to the bones like in New Super Mario Bros. with his Dry Bowser form. Then, King Boo which we see is actually just a Big Boo with a fancy crown, imitating King Boo. This can be canon due to the blue supernatural fire of Bowser, his Dry Bowser form (which also explains that regular Boos inhabit Dry Bones and are confused, when player beats them only for Boos to return into skeletons), and the gold portrait of King Boo, showing him and Bowser having a confrontation.
  • King Boo revives Bowser and they make an alliance against Mario Bros, so King Boo is able to revive Bowser anytime when he gets killed and takes his body until Bowser recovers. This version means that King Boo looks like a regular Big Boo because of the lose of his enchanted power-crown, which gives him incredible battle powers and creepy look. This can be canon due to the pose of Bowser in the portrait, like having sleep before King Boo inhabits him, and also gold portrait of King Boo, showing his confrontation with Bowser.
  • King Boo and Bowser are one and the same person. After his death, Bowser turns into a ghost, namely Boo, but still has some of his magic powers, which allowed him to bow Boos to his will. Then he recreates his body (or creates a very similar mech) to inhabit it. However, he wasn't able to fully recover, so he traps Mario, though fails in capturing Luigi. This theory provides a thought of Boo-Regent like the one in the first variant. This can be canon due to Bowser having good relationship with Boo and also quote of King Boo of Mario "giving him much troubles in the past". Also, this is can be consider canon, as Bowser still has powers to be revived, as it is done not only by himself, but by Bowser Jr., Koopalings, and Kamek on several occasions.
  • That the Bowser fought in Luigi's Mansion is actually a powerful illusion created by King Boo. In Luigi's Mansion: Dark Moon, Boos are seen sealing Toads inside portraits and using "Spirit Balls" to make objects invisible. These paranormal phenomenons are referred to as illusions by Professor E. Gadd and King Boo is referred to as the Master of Illusions much later in the game. It could be possible that the previous game's final boss fight was some sort of illusion Luigi was trapped in and had to fight his way through in order to save his brother. (Perhaps the same could be said for the titular fake mansion itself.)



           Mario Villains

Koopa Troop
Bowser | Bowser Jr. | Koopalings: (Larry Koopa | Morton Koopa Jr. | Wendy O. Koopa | Iggy Koopa | Roy Koopa | Lemmy Koopa | Ludwig Von Koopa) | King Boo (Luigi's Mansion) | Boos

8 Bit Club
Wart | Mouser | Tryclyde | Fryguy | Clawgrip | Birdo | Shy Guys

Secret Society of X-Nauts
Sir Grodus | Lord Crump | Shadow Sirens | Shadow Queen

Count Bleck's Minions
Count Bleck | Nastasia | O'Chunks | Mimi

Smithy Gang
Smithy | Exor | Mack | Bowyer | Yaridovich | Axem Rangers | Blade | Boomer | Count Down | Cloaker | Domino | Clerk | Manager | Director | Factory Chief

King K. Rool | Kremling Krew | Klump | Krusha | Krunch | Klubba

Antasma | Army Dillo | Ashley | Bonechill | Brobot | Broodals | Cackletta | Chuckolator | Cortez | Dark Star | Dimentio | Dino Piranha | Donkey Kong | Doopliss | Draggadon | Eely-Mouth | Elder Princess Shroob | Fawful | Gooper Blooper | Grubba | Kent C. Koopa | King Bob-omb | Necky | Wizpig | Kaptain Skurvy | Mechawiggler | MegaBug | Mollusque-Lancuer | King Kaliente | Mr. L | Nabbit | Petey Piranha | Peewee Piranha | Phantom of the Bwahpera | Rabbids | Rabbid Kong | Ruined Dragon | Shroobs | Tatanga | Torkdrift | Sunnycide | Squizzard | Viruses | Waluigi | Wario | Wracktail | Wingo