I vote for troll
the pic is impossible to see anything other than a grey blob and some green maybe leaves of some sort

now if you have some better pics we like looking at poo here.... critters that use caves or dens would tend to be skunks, possums, coons, bats, mink, or that other weasel critter...marten .... every cave or den i ever have run across has been pretty well vacant and not much left behind

bats are one that will fill their sleeping area with dung most critters are not huge fans of crapping where they sleep
