As stated in "Who is Michael Afton?" Michael is part of the Afton family. This family consists of Elizabeth, the youngest daughter, BV, the middle son, Michael, the oldest son, and finally, William, the father.
They were not the best family. William most likely had some form of mental illness, as he was not very sane. William had a business partner named Henry Emily, whom had a daughter named Charlotte Emily. Together the two opened Fredbear's Family Diner, a perfect place for kids birthday parties. The main attraction at Fredbear's was something called Springlock Suits. These suits functioned as both animatronics, and suits. Due to the success of Fredbear's Family Diner, William opened up two other locations, Freddy Fazbear's Pizza, and Circus Baby's Pizza World. Although, Circus Baby's Pizza World was not quite as innocent as it seemed. As stated earlier, William was not very stable mentally and who knows why. The animatronics at Circus Baby's Pizza World had some questionable design choices. These animatronics were made to kidnap and potentially kill children. William did not let his children near the animatronics for this reason, but Elizabeth, who was fascinated by Circus Baby (one of the animatronics) got too close and was killed by her. This devastated Michael and he took out the guilt on his younger brother through bullying along with his friends. Then on his younger brother's birthday (which was at Fredbear's) they dragged him to Fredbear's mouth and put him in it. Fredbear then bit down on Michael's younger brother's head which later killed him. With the loss of his two children on his shoulders, William was driven mad. He went to Freddy Fazbear's and put on the Spring Bonnie suit. He lead 5 children in to the back rooms and murdered them. He was not caught because he hid the bodies in the animatronics. Later on he was springlocked while trying to hide from the souls of the children while they were chasing him.
