Bulboos are sub-species of Boos. Debuted appeared in Super Mario Madness, they first appeared in a Ghost House of World 3, but become even more frequents in World 5. Unlike Boos, Bulboos have two behaviors; Bulboos who lives in Ghost Houses and Bowser Dimension will follow up Mario and friends when the characters are on their sights, and others who lives in Electro Factory will moves if the Switch Block is off, and stops if the Switch Block is on. They looked like lightbulbs, hence their name. They also have a bulb-like tail attatched on them, permit them to charges electronic balls as an attack. Their whole body, including their tongue and teeth, are made of glasses.
Bigger counterparts are Big Bulboos and Bulbemoth, and are rarer than the normal Bulboos. Unlike Boos, Bulboos love both light and darkness, and can be only defeated if the character punches them on their back when they don't charges electric balls (the Super Mario 64 logic is applied in Super Mario Madness for Boos, Bulboos and other Boo species, which won't disappear when exposed in lights and become vulnerable from their back).
While being less shy than most Boos species, they are also hasty; they moves faster than most Boos but will only go straight when it saw enemies.
This is their first appearence, and as explained, they appeared the first time in World 3's Ghost House. In the hall, they gather and chases the character, forcing the latter one to either jump or use it's Power-Up. Big Bulboos and Bulbemoth also appears in this game, where they serves as bigger and rarer counterparts. Normal Bulboos will help out Alex Ember Koopa when he is mad in Electro Factory.
- Bulboos and their larger counterparts are the only Boos who are not afraid and immune of lights, since they can produces them.