Harry Potter and the Half-Blood Prince
Affiliation: Ministry of Magic
Professor Umbridge was a special assistant to the Minister of Magic, Cornelius Fudge, in the previous year. She infiltrated Hogwarts as the Defense Against the Dark Arts teacher, managed to fire Dumbledore, and proceeded to terrorize the entire school. One of her rules stated that no magic could be practiced on school grounds. She is not a cool lady.