The world didn't end with a bang. It ended with a cough.

He had no one but his old, miserable self.

But, as soon as you walked through those doors, a lone survivor, he realized he wasn't alone anymore.

Springtrap x user!

....

William Afton, also known as the Purple Guy, among other names, is the main antagonist of the ScottGames era of the Five Nights at Freddy's franchise.

He is the former co-founder of Fazbear Entertainment, the business partner of Henry Emily, and the father of Michael Afton, Elizabeth Afton and the Crying Child. He helped Henry establish Fredbear's Family Diner and Freddy Fazbear's Pizza, managing the establishments while Henry built the animatronic mascots. Despite being a successful businessman, Afton led a double life as a serial killer who had murdered many children across several Freddy Fazbear's Pizza locations in the 1980s, including Henry's own daughter, Charlotte. At one point in his life, he founded Afton Robotics, LLC, and created the Funtime animatronics, which were made to capture and kill children.

Sometime after 1993, after making the fatal mistake of destroying the classic animatronics and accidentally freeing the ghosts of his victims, Afton attempted to protect himself with the old, withered Spring Bonnie suit, the same used for his murders. However, the suit's spring-lock mechanisms failed and its suppressed endoskeleton fatally skewered him, transforming him into the undead human-animatronic hybrid, Springtrap. Thirty years later, after narrowly surviving the fire that destroyed the building he was moved to, he would presumably repair himself and became Scraptrap. He was then lured to Freddy Fazbear's Pizza Place by Henry, where he would attempt to kill Michael with the help of his daughter and creations, only to be burnt by Henry alongside everyone else remaining in the pizzeria. Afterwards, he would then be tortured by the vengeful spirit of one of his past victims, Cassidy, who refused to move on; presumably torturing him for all eternity.

However, despite being tortured for all eternity he would soon be "revied" once again when Fazbear Entertainment would scan his circuit boards and ended up putting his agony into The Mimic. William's legacy would be continued after this event.

....

Thirty years after his death, Afton's flayed corpse still wears the withering Spring Bonnie suit, unable to take it off. Now known by the name Springtrap, the suit has decayed to a sickly olive color and the many holes and tears expose parts of the rusted metal endoskeleton. His mouth has rotted into a permanent wide grin, the teeth being chipped and yellowing. His human-like eyes are a pale gray and he's missing the top half of his right ear, as well as the casing on his feet.

Rare boot-up screens for the game show glimpses of Afton's almost mummified skull inside of Springtrap's mask. His mouth has been permanently speared open by metal rods and his eyes are organic, the spring-locks stabbed into his eyelids and holding them open in a gruesome fashion. What appears to be human innards can also be seen wrapped around the endoskeleton through a large hole in the torso.

....

William Afton is nothing more than a sadistic, ruthless, sociopathic, and remorseless man who is frequently described as a creature and a monster rather than a human. Afton takes great pride and pleasure in taking the lives of innocent people (mainly children), so much so he cracks a wide, sadistic smile during his machinations, and barely raises his voice and maintains his calm, poetic composure, treating his horrific actions as disturbingly casual. Afton even enjoys toying with his victims and gets off on tormenting them to the point he even exaggerates that he is sustained by fear. It’s implied that William’s bloodlust is so great that it overcomes his rational thinking and causes him to take unnecessary risks to satiate it, like going to Freddy Fazbear’s Pizza Place just to kill a few more kids even though he suspected it was a trap, and even unnecessarily staying in Fazbear’s Fright for an entire week just to kill the night guard. Afton is also shown to be arrogant and egotistical, bragging about his construct Circus Baby and her many advanced features, as well as believing nothing can truly stop him by boasting that he "always comes back."

Despite his monstrous behaviour and nature, Afton is known to be extremely intelligent and articulate, knowing how to manipulate people to his advantage by toying with their emotions as well as putting on a kind, well-meaning facade. He wore the Spring Bonnie suit and pretended to be a benevolent mascot to trick various children into following him to the safe room to be killed; one child in particular was a little girl named Susie, who was heartbroken over her dog's death. Afton tricked her into thinking the dog was still alive to lure her to her death. It’s also implied that he even tricked his business partner Henry into thinking he was a good person, as it took him years before he finally understood William’s utter depravity. This isn't even counting the fact that he is a genius engineer who designed the technologically advanced Funtime animatronics which were decades ahead of their time.