
The hidebehind from Fearsome Critters (1939).
Description
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The Hidebehind is a nocturnal creature that lurks in the woods to capture unsuspecting prey...namely, humans who wander into the woods. It is named for the fact it hides behind trees. It is generally agreed to be a dark colored creature, but details of it's appearance vary.
It only eats the intestines of it's victims, and can be kept away with alcohol.
It is currently noted for appearing in the popular cartoon Gravity Falls
Relation to Slender Man
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Additionally, many who watch the series Gravity Falls mistook the creature for a reference to Slender Man as a result of the obscurity of the folklore behind the creature.