Something took a big shit in our yard.

I don't know who or what it is but this morning there was a human sized shit in our backyard.
The only thing that makes me think maybe it wasn't a human is that there were some smaller pieces about
6 feet away from the main log.  I've seen dogs walk around while they shit, but usually humans stay rooted to one spot.  There were big green flies on it this afternoon, so before me or the kids trod on it, I picked it up with an empty plastic strawberry container like Pacman eating a really disgusting power pellet, put it in a plastic bag and threw it all in the garbage can.
I wish I got pictures of the crime scene.