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).
The campaign to create the Purple Heart Stamp was started in January 2000 by Senator Bill Larkin (R-C, Cornwall-On-Hudson), a 23 year Army combat veteran. After a massive letter writing effort by the Military Order of the Purple Heart and other veterans organizations, the stamp was first issued in 2003.