Peeves

Peeves is a poltergeist living in Hogwarts, a fictional setting in the Harry Potter books by J. K. Rowling. Peeves loves to cause mischief as his name implies. He does not listen to Hogwarts prefects (to Percy Weasley's great displeasure), teachers or anyone else, except for the Bloody Baron. For some unknown reason, the Bloody Baron is the only one who can control Peeves. Argus Filch works countinusly to try to get Peeves thrown out.

Peeves has not appeared in the movies so far.

Dolores Umbridge's atempts to take control of Hogwarts in Harry Potter and the Order of the Phoenix were met with insurrection, mainly from Fred and George Weasley. After the twins escaped from Umbridge's iron hand, one of them said, "Give her hell from us, Peeves." This may be the only time which Peeves ever obeyed a student.