Harry Potter
Severus Snape (Alan Rickman): Severus Snape was the Potions master at Hogwarts for the first five books. In the sixth book, he gets the position of Defence Against the Dark Arts professor. After the death of Dumbledore, Snape becomes headmaster. Throughout the books, Snape shows much bias for his own school house, Slytherin. He treats students from the other houses very badly.