Watch FMovies. In 2012, the horror character Slenderman exploded on the internet, becoming a beloved symbol across horror, video games, memes, independent art movements, and even Hollywood films. However, none of this was to last, as the movement behind Slenderman came crashing down in the wake of the 2014 Waukesha Slenderman Stabbing; a national news story centered around two children stabbing their classmate as an attempted sacrifice to Slenderman.