William Afton

William Afton (also commonly known as Purple Guy, The Killer, or The Murderer, or Mr. Afton) is the overarching antagonist of the Five Nights at Freddy's series and a reoccurring antagonist in The Garola and Frumple Show. He is one of Bill's best friends next to Harold and Mort. His undead alter-ego is Springtrap, who, in the show, is separate from him as another character. His archnemesis is Freddy Fazbear.

He was responsible for The Missing Children Incident mentioned in Five Nights at Freddy's, and he may have carried out more murders, as implied by the Death Minigames in the second game. He appears in most of the Death Minigames of the second game and the End-of-Night Minigames of the third and fourth game, and his role in the franchise's story is pivotal.