Unknown gender (Presumably male)
Boolossus, the Jumbo Ghost, is an enormous Boo and one of the portrait ghosts in the game Luigi's Mansion. He makes his appearance on the balcony. Luigi must face him as the third boss of the game.
Physical Appearance and Personality
This ghost leads a squad of fifteen regular Boos. He and his minions can combine their power to create his powerful form. Although these Boos are normally timid and shy, when they form into Boolossus's powerful form, all their fears disappear. Boolossus himself is a servant of King Boo, leader of the Boos, and is the guardian of the third area of Luigi's Mansion. His name is a portmanteau on the words "Boo" and "colossus" and literally translates to "Giant Boo". Unlike other Boos, Boolossus has glowing yellow eyes, which gives him a more menacing look. In the gallery, the portrait number of Boolossus is 22.
Luigi's Mansion series
Before the events of Luigi's Mansion, Boolossus was captured by Professor E. Gadd during the professor's travels around the world. E. Gadd used his Portrificationizer to transform Boolossus into a painting and placed the painting in his gallery of other portrait ghosts. However, the capture of Boolossus greatly angered King Boo. In retaliation, King Boo led his Boo minions in an assault on Professor E. Gadd's laboratory. The Boos reversed the setting on E. Gadd's Portrificationizer and reverted Boolossus' state. King Boo then ordered that all the other portrait ghosts that Professor E. Gadd caught should be freed as well. Eventually, after all the portrait ghosts were released, King Boo created a mansion, right next to E. Gadd's laboratory in Boo Woods.
In Luigi's Mansion, Boolossus, along with the other Boos (including King Boo), rests in a secret area under the Storage Room. When Luigi activates a hidden door in the Storage Room, the Boos spring out. However, when they notice E. Gadd's Poltergust 3000, a ghost-catching vacuum device, on his back, the Boos decide to run off and hide in the mansion.
Eventually, as Luigi makes his way through the mansion, he makes it to the Balcony. If he has not captured 20 Boos, however, he will be blocked in the hallway leading there by a particularly-transparent Boo, referring to itself as "the mysterious power of the Boos," which will then whisk him back to the Foyer. However, if he has captured the required amount, he can go through. While Luigi is there, his Boo Radar on the Game Boy Horror starts flashing intensely, indicating a powerful Boo presence. To the left, fifteen Boos are circling each other. Once Luigi approaches, they taunt him, followed by beginning to circle around him. They then whisk him away to an ethereal version of the Balcony, where the Boos merge into Boolossus's powerful form (which Boolossus himself calls "their real form") and swoop down upon him. Luigi then screams as he and his opponent are about to face off.
During the battle, Boolossus attempts to slam into Luigi with all his might, dealing decent damage. To defeat Boolossus, Luigi must use his Poltergust 3000 to pull Boolossus into one of the two stationary unicorn ice sculptures located on the balcony. When Boolossus touches the statue's sharp horn, his body pops, separating into the fifteen normal Boos (that is, Boolossus himself and his squadron). Luigi must then absorb an Ice Elemental Ghost from the ice sculpture and spray frost at the Boos, freezing them. This enables him to suck them into his Poltergust 3000. Eventually, Boolossus reforms with a lower number of Boos. His movement becomes faster every time several of the Boos are sucked up. However, if Luigi keeps popping Boolossus and freezing the small Boos, he can slowly drain Boolossus' power. As more and more Boos are caught, the other Boos become more wary of the Poltergust's ice blasts and flee when the ice blasts get too close to them. Once his 14 minions are captured, Boolossus cannot reenter his powerful form. Boolossus's final phase has 1 hit point.
After capturing Boolossus, Luigi acquires the key to the West Wing of the mansion. Defeating the boss counts as capturing a total of fifteen of the fifty released Boos. After the battle, Luigi visits Professor E. Gadd's lab and turns Boolossus into a portrait.
Boolossus does not have much of an artwork change in his appearance in the 3DS port. His mouth, however, has four sharp teeth.
Luigi's Mansion 3
Boolossus makes an appearance in Luigi's Mansion 3 as the top floor boss in the ScareScraper. His attack pattern is more reminiscent of King Boo this time, such as zapping the floor with Lightning, swiping his tongue over the platform, creating a shockwave by slamming the platform, summoning bombs which must be knocked back into his mouth to cause him to break off from his minions, which causes him to shrink into his small form. Before the Boos can regain their senses, Luigi must use his Poltergust G-00's slam technique to weaken the enemies. Once Boolossus is rendered solo, he cannot reform into a powerful Boo. He has a time crunch of 10 minutes during the battle.
Mario Kart series
Boolossus' gold frame portrait makes a cameo on the walls of Luigi's Mansion battle course of Mario Kart: Double Dash!! Aside from Chauncey, a few gold frame portraits of Boolossus are shown in the mansion segment of the Luigi's Mansion course in Mario Kart DS. These cameos were removed when the course was ported to Mario Kart 7.
- Boolossus has the least stamina of the Portrait Ghosts. He has only one in his final phase. To compensate, however, Boolossus has a complex strategy.