|Universe||Super Mario Bros.|
|Official Debut||Luigi's Mansion (GameCube, 2001)|
|Home Stage||King Boo's Illusion|
King Boo is a ghostly character from the Super Mario Bros. series who makes his Smash debut as a newcomer in Super Smash Bros. Universal Struggle. He was revealed during E3 2015 with a trailer titled "Ghostly Master of Illusions", which can be found here. King Boo is a lightweight character (although the Mario Kart series considers him a heavyweight) with some moves that can shake up the course of the battle dramatically. Because he is the master of illusions, King Boo is also a very stealthy character who can pull off some major combos.
- Neutral Special: Fear Factor - King Boo vanishes into the background and is able to sneak up on opponents and attack. King Boo is invulnerable during this time, but he cannot remain in the shadows for too long. King Boo can also stun opponents before he attacks. (4% damage)
- Side Special: Phantom - King Boo speeds forward with after-images being left behind him. The after-images do less damage then King Boo when he lands a hit after the dash. (9% damage from after-images and 12% damage from a head-on hit)
- Up Special: Ripple - King Boo leaps in the air and then slams onto the ground. Two spiked balls appear at either side of him and a ripple effect briefly appears on the platform he's on. The ripple both gives the balls motion and pushes back players. (15% damage from ripple, 0% damage for ripple effect, and 6% damage from spiked ball hit)
- Down Special: Bootrap - King Boo's crown charges up energy before it releases into the ground, creating either some sticky white goo or a patch of spikes near King Boo. The goo slows down opponents and makes them unable to jump or use Up specials.(0% damage for goo and 8% damage from spikes)
- Final Smash: Portrification - King Boo summons a picture frame held by two Boos and then traps an opponent in them by pressing B. The opponent trapped in the picture frame takes damage and is helpless as King Boo mercilessly throws them off-stage. He can also trap the remaining opponents in other picture frames, but these are weaker and can be easily escaped by button mashing. (44% damage for first victim and 22% damage for others)
- Neutral Special: Jump Scare - King Boo vanishes for a few seconds and then reappears in front of an opponent, scaring them into submission. This doesn't do any damage, as it simply stuns the jump-scared opponent for a few seconds, giving King Boo enough time to attack.
- Side Special: Goop Roll - King Boo rolls around while covered by goop from Super Mario Sunshine, similar to Yoshi's Egg Roll move.
- Up Special:
- Down Special: Lucky Trap -
- Up Special:
- Down Special: Fruity Roulette -
- Neutral attack: King Boo shoots out two beams of ectoplasm and then finishes with a headbutt.
- Dash attack: King Boo does a weaker version of his side special, save for the after-images. (10% damage)
- Forward tilt:
- Up tilt:
- Down tilt:
- Forward smash: A Strong Sneaker ghost appears in front of King Boo and smashes their hands. (20% damage)
- Up smash: King Boo shoots a wave of blue fire from his crown overhead. (4% damage per hit and 12% damage if all hits connect)
- Down smash: King Boo hovers for a second and then slams down, resulting in a ripple effect. (7% damage)
- Neutral aerial:
- Forward aerial:
- Backward aerial:
- Up aerial: King Boo swings himself upward, similar to a leaping headbutt. (9% damage)
- Down aerial: A Slammer slams down his fists. (11% damage)
Grabs, Throws, and Pummel
- Grab: King Boo sends out a Slammer to grab the opponent.
- Pummel: The Slammer slams his fists into the opponent rapidly.(4% damage per hit)
- Forward throw: King Boo throws his opponent forward using a beam of ectoplasm.(8% damage)
- Backward throw:
- Up throw:
- Down throw: