Boolossus, the Jumbo Ghost is the third major boss in the game Luigi's Mansion, found in Area Three. He is made up of fifteen normal Boo ghosts that combine together on the balcony upon Luigi's arrival. Boolossus earned his name from "Colossus" and "Boo".
After he has been defeated, the Diamond Key is given to Luigi. Approaching the Diamond Door on the Balcony will cause a power outage in the mansion, causing many ghosts to attack in the darkness, regardless of the room. Boolossus is seen as a large Boo. His only attack is bouncing. When he splits up, the boos he is made of will try to ram into Luigi, though most will flee. Boolossus will reform his body after 15 -- 30 seconds.
Luigi must pop Boolossus with the horn of the nearby frozen unicorn statues. He can then obtain an Ice Elemental Ghost from the statue. Luigi must then freeze the Boos, and after that he must suck them up.
- A similar boss appears in a mission in Luigi's Mansion: Dark Moon. In the mission E-4: Ambush Maneouvre, ten Boos join together to crush Luigi.
- Boolossus is also similar to the Atomic Boo from Paper Mario: The Thousand-Year Door. However, the Atomic Boo is composed of 200 Boos and Boolossus is bigger.
- Boolossus is also similar to the boss Jalhalla from The Legend of Zelda: The Wind Waker, both bosses being large ghosts comprised of many smaller ghosts.
|Big Boo • Bigger Boo • Black Boo • Boolossus • Boos in Luigi's Mansion • Boos in Luigi's Mansion: Dark Moon • Bootler • Franky • Herbert • Igor • King Boo • King Boo (Super Mario Sunshine) • Lady Bow • Lahla • Peeka • Spooky Speedster • Stanley • The Creepy Steeple Boo|
|Balloon Boo • Big Boo • Big Boo (Paper Mario) • Big Frame Boo • Big & Little Boo • Blindfold Boo • Bomb Boo • Boo • Boo Balloon • Boo Block • Boo Buddy Snake • Boo Buddy Swarm • Boo Guy • Boohemoth • Boo Man Bluff • Boo Stack • Calm Fishin' Boo • Circling Boo Buddies • Dark Boo • Dark Dark Boo • Disappearing Boo Buddy • Eerie • Fishin' Boo • Frame Boo • Ghoul Guy • Gold Boo • Green Boo • Li'l Boo • Mad Big Boo • Mad Boo • Mini Boo • Octoboo • Peepa • Phantom Guy • Red Boo • Shiny Boo • Sleepy Boo • Snufit • Stretch • Tail Boo • Terekuribō|