The Ugly One - What Is It?!?

Looks like a mustelid (member of the weasel family) of some sort with its hair slipping due to decay. The head shape and musculature look like a mustelid for sure. If I had to hazard a guess, I would say is a mink (the hair length and texture seem right). If the hair were shorter I might guess an otter. Nothing really mysterious about it to me.