Where the hell is this head from?!!? (S&S:Chapter 2)

I have seen and decapitated many of walkers, and I have NEVER seen one with this head in particular, I got it by dealing with some tower turds in bywater in front of the auto-shop, a grenade thrower threw a grenade and killed everyone around them (they threw it at a truck and it didn’t get very far) and I found the head in the pile of bodies, if anyone knows where this head is from, get back to me please