Slender Man (alternatively spelled as Slenderman) is an Internet urban legend that debuted on the SomethingAwful forums in 2009, and since become the titular main antagonist of its own mythos series.
He is widely recognized as a sort of pop culture icon and also a somewhat controversial figure, considered a prime example of a Creepypasta villain at its best, being featured in many fictional stories around the web. The Slender Man's motivations vary depending on the version, but the original has him as a monster that despises humanity and takes pleasure in sadistically torturing them before devouring them. A small group of people believe that he is real and have reported sightings from diverse locations.