Is the Main Antagonist of FNAF Series and Main Antagonist of the Upcoming Film under the Same Name.
An unknown man emerged in Freddy Fazbear's Pizza with plans of death and chaos for the company. One day, in Fredbear's Family Diner, as Fredbear was serving cake to the children, a girl was crying outside because she was locked out of the restaurant by three other children. As she cried, William drove over in a purple car and murdered the girl.
Fredbear was unable to protect the child. With that, Purple Guy drove away, leaving the child's corpse outside. The girl's spirit, possibly driven by revenge, and a desire to help William's other victims, was theorized to have possessed an animatronic a certain time after that, known as The Puppet. Fredbear's Family Diner was then shut down.
Later, in 1983, Fazbear's Entertainment opens Freddy Fazbear's Pizza, introducing Freddy Fazbear, Bonnie, Chica, and Foxy as the new mascots. These new animatronics were added alongside the original Fredbear and Spring Bonnie characters, which were made as spring-lock suits that doubled as both animatronics and costumes that a person could wear. William returned to the restaurant and wore the Spring Bonnie suit to lure five children, one by one, into the establishment's Safe Room before murdering them. Afterwards, The Puppet, possessed by William's first victim, stuffed the corpses of the five children into the Freddy, Bonnie, Chica, Foxy, and Golden Freddy animatronics, allowing their spirits to possess them.
- The markings across Williams body are scars from a previous Spring-lock incident which he survived.
Although William prefers to lure kids in the Spring-Bonnie costume, in the novels he uses the Spring-Fredbear costume as well.
The reason Afton is known as "The purple man" is because before graphic illustrations were made, he was only but an 8-bit sprite of a smiling purple man. Dubbed "purple guy" by fans.
Before he was given an official name in 2015, fans referred to the killer as "Vincent" during 2014 and early 2015.