Unlike the unicorn or the griffon, you won't find these monsters in old fairy tales. That's because the swamp booger, also known as an "assquatch," is just another Island Of Dr. Moreau reject birthed by "gaff taxidermy" -- the disturbingly inventive branch of taxidermy. Creatures like the swamp boogers are simply "an outlet for a taxidermist's weird creativity," noted taxidermist Ryan Biracree told Vice. After all, if you don't get into stuffing animal carcasses to look like eldritch abominations come back to pseudo-life for the art of it, then what are you doing with your life?
So if the swamp booger / assquatch isn't made from the hide of some mythical creature, then what is it made from? As it turns out, the most common taxidermist treasure of all: surplus deer ass. Trophy hunters only tend to be interested in hanging up the front end of a deer, with their glorious antlers and dead, judging eyes. This leaves taxidermists with a lot of deer rears to fool around with. So sometimes they stretch the backside out, cut eye holes out of it, and pucker the anus up to serve as a mouth. And if you like things that look like if the Grinch got bitten by a were-skunk, the results are stunning.