A Boo Ball is an item in Luigi's Mansion. While exploring the mansion, Luigi may follow the Game Boy Horror's signal to a Boo, only to find one of these decoys instead. Boo Balls are nothing more than white spheres with the face of a Boo printed on them. They do not harm Luigi, but he can suck them up onto the nozzle of his Poltergust 3000 and blow them out again, destroying them. Either this or a bomb appears.