One day in the winter of 2003-2004, as I was coming back to my apartment, I passed this on the landing. So I had to take a picture. Yes, it's a cow's skull.
Need I say more?
Okay - I will. The pipe on the right is the garbage chute, but as you see, people don't always bother to put the garbage down the shoot. I'm not sure the head would have fit anyway, what with the horns and all.