One of Severus Snape's first quotes is a subtly loaded piece of dialogue. The Hogwarts professor has no shortage of great lines, including his biting sarcasm, dry humor, and consistent condescension of his students. It's for that reason that his reveal as a more complex, tragic double-agent in Deathly Hallows: Part Two is widely recognized as one of the most important plot twists in Harry Potter. Even with characters like Neville Longbottom and Draco Malfoy, Snape's character arc is easily the most fascinating across all eight movies.