Harry Potter and the Order of the Phoenix
by J.K. Rowling
Pansy Parkinson is a Slytherin fifth year, a prefect, and (eventually) a member of the Inquisitorial Squad under Professor Umbridge. She is really attached to Draco and (of course) hates all Gryffindors. At the end of the novel, as the students continue to rise up against Professor Umbridge and her unjust reign, Pansy winds up missing class for a day after growing antlers (30.5).