That was just done as a prank. I found a dog, and cut it open just to see what The insides looked like, and for some reason I thought it would be a fun prank to stick the head on a stake and set it out in the woods. And brought one of my friends back to look at it and said I'd stumbled upon that in the woods. Just for shock value….I wasn't into any occult then, it was just a prank.
Dahmer explains why the head of a dog on a stick in the woods behind his house was not an occult ceremony but a prank.