The Bloody Baron is the ghost of Slytherin House in the Harry Potter series created by J.K. Rowling. A thousand years ago, he was in love with Helena Ravenclaw, the daughter of Hogwarts founder, Rowena Ravenclaw. He was sent to find Helena when Rowena was dying, and, when she refused to return with him, he stabbed and killed her. Upon seeing her dead, he stabbed and killed himself, leaving bloodstains on his clothes. He wears the bloodstains to remind himself of his shame. He is described as a grim, silent, and terrifying specter. In the books, we never hear him speak but he is the only one who can control Peeves the Poltergeist. In the movie, he is seen laughing and acting somewhat frivolous.