Graham Montague

Montague is named as a Slytherin Chaser in Chapter 15 of Harry Potter and the Prisoner of Azkaban. The first notable thing that he does is grab Katie Bell by the head (accidentally) instead of the Quaffle. He is mentioned again in Harry Potter and the Order of the Phoenix, when we are told that Fred and George forced him into the Vanishing Cabinet head-first, after he tried to take fifty points from Gryffinder. He was also a member of the Inquisitorial Squad.