It was a C.H.U.D.
A C.H.U.D. that somehow got lost from the sewers, wandered into the woods and basically adapted to its surroundings for the past twenty something years.
So you folks better be careful. The terror of the Cannibalistic Humanoid Underground Dwellers still haunts us to this very day.
"What's the ugliest part of your body? I think it's your mind."