Bomb Boos are an explosive, black-colored variety of the Boos that debuted in Super Mario Galaxy. They later make a reappearance in the Mario & Luigi series during the Minion side modes.
In Super Mario Galaxy, Bomb Boos only appear in the Ghostly Galaxy during the missions Beware of Bouldergeist and Bouldergeist's Daredevil Run, where they are necessary to defeat Bouldergeist. Bomb Boos float lazily back and forth, exploding after some time, but they do move towards Mario or Luigi if either of the Bros. get close to them. If the player spins near one, Mario or Luigi will grab its tongue, and continuing to spin will swing the Boo around until it hits something or they eventually lose their grip.
Up to six Bomb Boos can be held at once. If the player holds it for too long, it will begin to flash red and explode soon after, damaging Mario or Luigi.
In Super Mario Galaxy 2, Bouldergeist re-appears, along with four other Super Mario Galaxy bosses, in the Boss Blitz Galaxy. Because of Bouldergeist's reappearance, Bomb Boos make a comeback so Mario can damage the boss in the same way as he did in the previous game.
Bomb Boo makes an appearance in Dr. Mario World as an assistant doctor. In stage mode, they grant a chance in increasing the capsule amount by three when the player has only three capsules remaining, in which the chance of activating it is greater at higher levels, up to 25% at maximum level. If this effect failed to activate the first time, it will attempt to activate with the same percentage chance if the player's capsule amount exceeded this amount and then reduced to three remaining capsules again. Once this effect activated, it will not activate again for the duration of the stage. In versus mode, they grant a chance that the skill meter will be half-full at the start of the match, in which the chance is greater at higher levels, up to 90% at maximum level.
Profiles and statistics
Mario & Luigi series
Mario & Luigi: Superstar Saga + Bowser's Minions
Minion Quest: The Search for Bowser profile:A rare type of Boo that explodes! They are especially red.
Mario & Luigi: Bowser's Inside Story + Bowser Jr.'s Journey
Bowser Jr.'s Journey profile:A rare type of boo that goes kaBOOm! After exploding, they won't return until the next battle. Keep that in mind!
Dr. Mario World
Stage mode: "Grants 5%/10%/15%/20%/25% chance of extra capsules (3) when the number of capsules remaining reaches 3."
Versus mode: "Grants 50%/60%/70%/80%/90% chance of half-full skill meter on stage start."