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).
About FNatF games. Five Nights at Freddyâs games (shortly called FNaF games) are scary adventure games developed and created by Scott Cawthon. These games are so popular and famous all over the world, and for that reason, there have been so plenty of fan creations based on the original series.