Purple Guy, known in canon as William Afton, was the father to Elizabeth, Michael, and the Crying Child (presumably named Evan). Having been introduced to the EthGoesBoom franchise in 2016, Afton was the main antagonist, and still is in the canon series. In the EthGoesBoom universe, he was able to tamper with the A.I. of Withered Freddy, attempting to disguise in the Shadow Freddy suit.
In the 1970s, Afton ran Fredbear's Family Diner with his business partner and friend, Henry Emily. Afton went on to have three children, and Henry had a daughter named Charlie. Evan, Afton's youngest son, was bitten to death in the jaws of Fredbear after being shoved into the animatronic's mouth by his older brother, Michael; Elizabeth, Afton's only daughter, was killed by Circus Baby after she went to close, despite her father's warnings not to.
The deaths of his children drove Afton to madness, leading him to kill the children of other families out of grief and revenge. This began with Charlie, the daughter of Afton's closest friend, who then went on to possess The Puppet. Afton then went on to kill five (perhaps even more than that) other children, stuffing them into the suits of the animatronics in Freddy Fazbear's Pizza.
After laying low for six years, Afton emerged again in 1993 in an attempt to finish the animatronics off once and for all. At first, it seemed as if he would succeed, as he was easily able to dismember Freddy, Bonnie, Chica, and Foxy However, everything changed when the spirits of the children Afton had killed began to haunt him. In an attempt to hide, Afton stuffed himself into an old Spring Bonnie suit, the springlocks clamping down onto him and killing him. He would stay in the backroom of Freddy's for thirty years before being reanimated as Springtrap.
As Springtrap, he has seen a significant change in character. After the animatronics, specifically Golden Freddy, put an end to his madness by turning back time to prevent the Fazbear's Fright incident, he was once again trapped in the saferooms. He was eventually let out after JJ persuaded the others that he had changed. This sparked a close friendship between the two, similar to that of Foxy and BB. Springtrap now plays games alongside the rest of the animatronics.