In some ancient civilizations the Wolf was a symbol of the underworld. In Egypt, the guardian of the dead was Anubis who was a wolf-headed god. The jackal portrayed as black was the symbol of both death and regeneration.
William is also the one who hid inside the suits and kidnapped and killed children, leading to the assumption that William Afton is The Purple Guy of FNaF 2 and 3 (he is killed at the end of the book when Charlie sets off the spring locks in his suit).
Robert Englund. Kane Hodder (in Jason Goes to Hell) Frederick Charles Freddy Krueger is a serial killer and the central antagonist of the Nightmare on Elm Street series. A family man on the surface, Krueger was actually the serial killer known as the Springwood Slasher.