Lord Voldemort (/ˈvoʊldəmɔːr/ VOHL-də-mor, /-mɔːrt/ -⁠mort in the films)[j] is a fictional character and the main antagonist in the Harry Potter series of novels by J. K. Rowling. He first appears in Harry Potter and the Philosopher's Stone (1997) and returns either in person or in flashbacks in each novel in the series except the third, Harry Potter and the Prisoner of Azkaban, in which he is only mentioned. Voldemort, an anagrammatic sobriquet for his birth name Tom Marvolo Riddle, is the archenemy of Harry Potter, who according to a prophecy has "the power to vanquish the Dark Lord". After killing Harry's parents, Lily and James Potter, he attempts to murder the boy, but instead leaves him with a scar on his forehead in the shape of a lightning bolt. Nearly every witch or wizard dares not utter his name and refers to him instead with such monikers as "You-Know-Who", "He-Who-Must-Not-Be-Named", or The Dark Lord. Voldemort's obsession with blood purity signifies his aim to rid the wizarding world of Muggle (non-magical) heritage and to conquer both worlds, Muggle and wizarding, to achieve pure-blood dominance. Through his mother's family, he is the last descendant of the wizard Salazar Slytherin,[6][7] one of the four founders of Hogwarts School of Witchcraft and Wizardry. He is the leader of the Death Eaters, a group of wizards and witches dedicated to ridding the Wizarding World of Muggles and establishing Voldemort as its supreme ruler.