List of Boos in Luigi's Mansion
In Luigi's Mansion, Luigi releases fifty Boos (fifty-one including King Boo). He must then catch each one throughout the game. Thirty-five of the fifty regular Boos are named and each one always starts out in a particular room (the other fifteen are smaller ones that form together to make Boolossus). Once Luigi uncovers a Boo, he must drain all of its HP with the Poltergust 3000 to capture it; however, there is a chance Luigi can uncover a Boo Ball or bomb instead. Boos are capable of fleeing to other rooms, forcing Luigi to chase them down. If a Boo escapes into a dark room or hallway, their HP takes longer to deplete. Some Boos tackle Luigi when threatened, while others do not. Luigi can still take damage from these on contact, however.
Luigi needs to catch 5 Boos to unlock the washroom on the first floor, 20 of them need to be captured to access the balcony on the third floor and battle Boolossus, and 40 of them need to be captured to fight King Boo (45 in the PAL Hidden Mansion). If Luigi manages to vacuum up all 50 Boos, the last one drops a Gold Diamond.
The following chart shows each Boo, its amount of HP, whether or not it has the ability to attack, the room it starts out in, the different hiding places in that room and the object or saying that the said Boo is based on. Note that if the game is turned off before any particular Boo is caught, it returns to the room it started in with all its HP restored.