He is the confirmed killer of 11 children. His story is told through 8-bit-styled minigames in Five Nights at Freddy's 2, Five Nights at Freddy's 3, a cameo in Five Nights at Freddy's 4 as well as hints through Sister Location.
Five Nights at Freddy's 2
Finally, he lured 5 children into the backroom using cake and a yellow suit. This is seen in Foxy GO GO GO. Then the Puppet stuffed them in Freddy, Chica, Bonnie, Foxy, and Golden Freddy suits to save their souls.
In the second game, he is implied to have been the nightguard before Jeremy Fitzgerald. He went to murder 5 more kids and messed up the 'Toy' Animatronics facial recognition software, which made them hostile to the employees of Freddy Fazbear's Pizza.
Five Nights at Freddy's 3
He returns in the third game, dismantling the classic animatronics one by one when they cannot enter the saferoom he is hiding in. However this unleashes the spirits of his victims who chase him in the Safe Room, and William puts on the Spring Bonnie suit, thinking that this will protect him. The locks come loose and kill him, turning him into Springtrap.
Five Nights at Freddy's 4
William appears in a cameo in the fourth game, putting someone in the Spring Bonnie costume in the back room.
He returns in Sister Location, which for the first time refers to him as William Afton. In the opening scene of Sister Location an entrepreneur is asking him questions about the new animatronics. They inquire why certain features were added and express their concerns, but he avoids answering the specific features they refer to.
He is also the creator of the animatronics and the former owner of the Circus Baby's Entertainment and Rental and, by extension, Circus Baby's Pizza World. William instructs Michael to go to the underground facilities and find his sister. This implies that William Afton is aware of the souls of the children staying behind, and knows his daughter's soul is within Circus Baby. As well as this William is seen as Springtrap leaving Fazbear's Fright in the Golden Freddy Mode Cutscene in the Custom Night.
Freddy Fazbear's Pizzeria Simulator
See main article: Springtrap
As well as being present as Scraptrap, William Afton appears in the Minigame Fruity Maze, wearing the original Spring Bonnie suit, and luring a girl away, with a promise to show her that her dog is alive. He may also be the Orange Man. He is also referenced by Henry as his "old friend" who started the restaurant chain.
The image of William Afton features as a playable character in the Update 2 of FNaF World, who is unlocked after beating FNaF 57. His dialogue implies he is not the actual Purple Guy "just a game sprite".
- William Afton's true physical appearance has never been revealed.
- In FNaF: The Silver Eyes, He is described as a thin man whose clothes seem big on him; he was once fat, but later lost weight as the years passed. He has scars on both sides of his neck and on his back. It is unknown how he got these scars, although they could possibly be from the springlock suit he wore.
- In the opening cut scene of Freddy Fazbear's Pizzeria Simulator, a man is depicted who could be William as he is wearing a blue-purple suit, has a cleft chin, like the one in Springtrap, and has a faked smile.
- For the longest time Michael Afton was thought to be the same entity as William Afton, but it was figured out in the final cutscene in V. Hard Golden Freddy mode (Custom Night) that he was not.
- William seems to have a British accent, with his Daughter and Son having one too.
- William seems to have (at least) 2 children: Michael and Elizabeth (whose remnant was inside Circus Baby). The Older Brother may be Michael, and the Crying Child would be the third child.
- William first appears in the Five Nights at Freddy's 2 Minigames, the Foxy Go! Go! Go! Minigame , the Take Cake to the Children Minigame. In the SAVE THEM minigame he looks very different, being a darker purple and thinner.
- His appearance in FNaF3 seems to be a mixture of his first two sprites.
- His FNaF 4 cameo seems closer to the SAVE THEM sprite.
- It has been speculated that William is the player in Ultimate Custom Night, with it being set in Hell.