Pure Evil Wiki
NOTE: This page is only about the Luigi's Mansion series version of King Boo as his Super Mario series/spin-off games incarnation was not voted as Pure Evil, and thus only the Luigi's Mansion series version of King Boo's info and crimes should be put here.

I am not afraid of you, fool! I fear only that infernal Poltergust 3000 you carry on your back! Stupid machine! But I am a KING among Boos! I swear it... I shall fear no mere house-cleaning device!!
~ King Boo prepares for the final battle in Luigi's Mansion.
Mwah ha ha! Now what do we have here? Why, if it isn't my old pal Luigi! Or is it Baby Luigi? I can't tell the difference. Hey, remember that time 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 shows up for the final battle in Luigi's Mansion: Dark Moon.

King Boo, also known as the Master of Illusions, is the main antagonist of the Luigi's Mansion trilogy.

He made his debut in the first Luigi's Mansion game as the archenemy of Luigi. As his name suggests, he is the king of the entire Boo race.

He was voiced by Toru Asakawa.

What Makes Him Pure Evil?

  • While he may have been a caring ruler at one point, this changes once Luigi beats him in the first game. This was made evident by the fact that he didn't bother to rescue his minions who were defeated and trapped in paintings like he did in the first game.
  • After his first defeat, King Boo 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.
  • Notably grew to care little for his troops as of Dark Moon, 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 homeworld with the intent to destroy the universe as an act of spite.
  • At the end of Luigi's Mansion: Dark Moon, he openly states that he plans on ruling the world using the corrupted ghosts, and that he'll kill Professor E. Gadd and everyone Luigi knows after he's done with him.
  • He also attempts to crush Luigi to death during the final battle with him in Dark Moon.
  • Sadistically taunted Luigi over the capture of his friends and family.
  • Despite only developing a grudge against Luigi and E. Gadd specifically, he still repeatedly went after their friends and family to permanently trap them in paintings too, either to hurt/get to them, or simply out of spite due to their association with them. First, he abducted Mario and several Toads in Dark Moon, then subsequently set a trap for all of them in Luigi's Mansion 3 where he once again temporarily succeeded in capturing them along with Princess Peach. This is especially evident in the case of Peach and the Toads since he had no reason to believe they were a threat to him.
  • Despite being freed by her, he showed no affection for Hellen Gravely or her efforts to impress him, openly stating that he wasn't confident that her plan would work when confronting Luigi, refusing to give her the opportunity to make up for her shortcoming and later disregarding her entirely for her failure upon her capture.
    • King Boo also treats Hellen Gravelly like she was just his minion/right-hand instead of a love interest, and he gets angry at her every time that one of her minions fail, meaning that he never loved Hellen. Additionally, he also decides to destroy her hotel, which is the last thing that she wanted.
  • He callously dismisses the rest of her staff as useless for failing to catch Luigi, despite his own lack of success attempting to do so in the past.
  • Focused himself entirely on removing his opposition to the point where he is willing to trap The Last Resort and everything around it inside a painting simply to capture Luigi.
  • Although the heinous standards of the series is pretty high, he still managed to stand out for the following reasons:
    • While there are multiple truly heinous villains in the series, most of them have at least some redeemable qualities and care for others, which makes King Boo worse as he threw away all redeemable qualities and care for people after the first Luigi's Mansion game. Not only that, but he still managed to commit worse crimes than most villains.
    • He is the most personally evil to the main protagonist in the series (Luigi) as he continuously captures his friends and family for his plans (even when they aren't a threat to him), as well as puts them in a fate worse than death by trapping them in paintings where they're aware of their surroundings, but are unable to move or do anything else.
    • Destroying the Dark Moon, which drove the ghosts of Evershade Valley insane.


  • King Boo is, along with the Shadow Queen (English), Princess Shroob and Dimentio, one of four Mario villains to be Pure Evil.
    • Out of the four, he is the only one who doesn't act as the main antagonist in an RPG title; however, his Mario version does appear as a boss in Mario & Luigi: Paper Jam.
  • In the first Luigi's Mansion, King Boo didn't seem to be pure evil, as he claimed to care for his fellow ghosts. However, he then became pure evil in Luigi's Mansion: Dark Moon, as he was willing to destroy all of reality solely out of revenge against Luigi, and remained pure evil in Luigi's Mansion 3, as he had shown to have discarded any affection for other ghosts.
    • It's possible that the magic crown he was wearing in Dark Moon affected his mind and turned him insane. However, whether or not this is true is unknown as this was never confirmed before--or even implied.
    • He isn't shown to be pure evil in any of the spin-off games either, as he calls little Boos cute and is merely helping Bowser and is on Wario's baseball team, not going beyond standard villainy. Not to mention Bowser wouldn't accept a Pure Evil in his ranks. That could be because the King Boo outside of Luigi's Mansion is a different Boo altogether. This is supported in Mario Kart Tour, as both King Boos are shown as playable since the Halloween 2019 update.
      • This might also explain why he looks different in the Luigi's Mansion series. (The crown on his head doesn't explain this because in the end credits of Luigi's Mansion 3, he looked the same and his crown was off him at the time.)
  • Despite being the first Pure Evil introduced in a Mario game, he was the last of the three to become Pure Evil. This is because Shadow Queen, Princess Shroob, and Dimentio started off with no redeemable qualities. King Boo started off with redeemable qualities in his first appearance such as caring for his troops. But that all went away by the sequel, making him officially Pure Evil.

External Links


           Mario.png Pure Evils

King Boo | Princess Shroob
Shadow Queen (English) | Dimentio

King Koopa | Dimentio (SPM2: TSS) | King Stiron | Kammy Koopa | Dimentio (MOTI)
Turbo Mecha Sonic | Sir Benedict Cumbersnatch | Maxwell Gaines

See Also
Nintendo Pure Evils | Nintendo Fanon Pure Evils