In recent days I've said it smelled like something died in our shed, and today I found it: a ~10 pound long haired cat or possum with its guts split by decomposition.
It was actually outside the shed, jammed between it and the fence. Because of the size of the space I had to have Smiley get in there with a shovel and drag it out to a point where I could reach it.
He wasn't easy to convince, and enjoyed it even less, but as Lisa said "You're going to be a man, and men have to deal with the ugly."
I buried the beast in the backyard.