List of Boos in Luigi's Mansion
During the events of 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 form together to make Boolossus). Once Luigi uncovers a Boo, he must drain all of its HP with the Poltergust 3000 to capture it. Boos are capable of fleeing to other rooms, forcing Luigi to chase them down. Some Boos will tackle Luigi when threatened, while others will not. Luigi can still take damage from these on contact, however.
Luigi needs to catch 5 Boos to unlock the Washroom (1F). 20 of them need to be captured to access the Balcony (3F) and battle Boolossus. 40 of them need to be captured to fight King Boo. If Luigi manages to vacuum up all 50 Boos, the last one will drop 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 will return to the room it started in with all its HP restored.