This is the most scary documentary than most horror movies, In 2014, two 12-year-old girls lured another child to the woods in Wisconsin and stabbed her 19 times. The two girls later explained that they were told to do it by the fictional character Slenderman. Now, this horror story is being made into an HBO documentary, coming to the cable network on January 23.
Slenderman was created in 2009 by Eric Knudsen on the Something Awful forums. There are many stories and art pieces featuring the fictional character, who is known for abducting, terrorizing, and stalking people, including children.
The trailer for Beware the Slenderman can be seen below.