The Dark Lord, He-who-must-not-be-named. Leader of the Death Eaters, You-know-who is the arch-nemesis of Harry Potter. Voldemort is known for his trademark disfigured face and long black robe. Novels in this series include Harry Potter and the Philosopher's Stone, Harry Potter and the Chamber of Secrets, Harry Potter and the Prisoner of Azkaban, Harry Potter and the Goblet of Fire, Harry Potter and the Order of the Phoenix, Harry Potter and the Half Blood Prince and Harry Potter and the Deathly Hallows. The perfect villain costume at Book Week and Halloween.