The HideBehind is a creature from American Folklore.
Description[]
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[]
The HideBehind is able to suck it's stomach in to make itself incredibly thin, making it able to hide behind anything. Both beings also lurk in the woods to capture unsuspecting prey. It also feasts on the intestines of it's victims, similar to how in the early Slender Man Mythos, Slender Man removed the organs of it's victims.
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.