Bloody Baron

From Hpwiki

The Bloody Baron is a ghost at Hogwarts, the house ghost of Slytherin. He has this nickname because his robes are stained with blood which now, him being a ghost, looks silvery.He loved Helena Ravenclaw (The Grey Lady, the ghost of Ravenclaw, anf the daughter of Rowena Ravenclaw) and when she ran away, he was sent to retrieve her. When he found her, she refused to go back with him. Furious, he killed her and then killed himself, using the same weapon.

The Bloody Baron is the only thing Peeves, the Poltergeist is afraid of. His real name is unknown.

Terence Bayler portrays the Baron in the Harry Potter movies.