Something Strange and Gross in Brain’s Backyard [PIC]

The strange tales from my backyard continue this spring. Yes, the occasional raccoon sightings continue from time to time. But something more disturbing happened this week. This past weekend my kids and some friends were playing in our backyard when Carly came running into the house and said that they had 'found teeth'. Yes, teeth. I ventured back to see what they meant and found the kids huddled around something in the grass. I bent down to see what appeared to be the lower jaw bone and teeth of a small animal. Judging by the size and shape, it appeared to be from a possum. I threw it away and searched the backyard for any other parts and found nothing. Flash forward to yesterday morning. My wife sent me this picture of what she found in the backyard.

That is the rest of the possum head. She found several other small animal parts too. What put them there? What killed the possum? Is the mob trying to send me a message by leaving an animal head in my backyard? My initial thoughts turn back to the raccoons. Would they kill a possum and scatter the parts all over? I also thought that our dog Rigby may have found a dead possum and had some fun with it, but I never found a carcass and we watch him very closely when we let him out. So the strange happenings in our backyard continue. Raccoons and dead animal parts. What's next?