I looked for tracks, but it's a grassy area and no tracks were evident. I've got one of those new Moultrie Trail Cams that you can set for short videos. Next hog I get (unless it's a nice sized edible female) goes in exactly that same spot, with the new camera pointed at it.
I put a camera over a dead hog a few years ago, and it was coyotes doing most of the eating, but the best camera shot I got was a coyote looking right into the camera lens while taking a dump. You don't think those guys have that much intelligence, do ya? I'd show you the pic, but somehow I erased it a year or two ago.
So probably it was coyotes, but geez...how many coyotes does it take to eat 120 pounds of pig in such a short time? That's a lot of meat and guts.