Slender Man was created as the result of an image manipulation thread on the Something Awful online forums. The aim of the thread, titled "Create Paranormal Images", was to edit photos to include some kind of paranormal phenomena and have them pass as looking genuine. On June 10th 2009 the user Victor Surge posted two black and white pictures of children with Slender Man behind them and the character was born. Victor Surge and Something Awful users continued to create images and add backstory to the character. Since then Slender Man has appeared in photo manipulations, video series, written fiction, fan art, and more.
Ten days after the first post of Slender Man images, a Something Awful user going by Ce Gars claimed that he had some tapes that a friend had given him, that had something peculiar on them. This was the start of Marble Hornets, a strong influence on all following interpretations of the character. The three primary creative forces behind Marble Hornets would go on to write the story for Slender: The Arrival, in which Surge served as executive producer.
Appearances in Games
Slenderman: The Video Game (aka Slenderman: The Game) was the first attempt at placing the character into a video game setting.
In Slender: The Eight Pages, the player is trying to collect a number of manuscripts relating to the creature, not dissimilar from those that can be seen in the web series involving the creature, Marble Hornets. Here Slender Man is capable of teleporting around the world and should the player view him for too long their screen will fill with static and they will be caught by him. Many other games have copied this concept, tasking the player to collect 8 objects while eluding Slender Man.
On 9/18/2012, farming sim/virtual pet "Zombie Pets" released Slender Man (under the name of "Slim Guy Zombie") as a collectable pet.
Slender Man also served as at least partial inspiration for the Minecraft enemy known as Endermen.
Appearances in other Media
The Slender Man myth makes an appearance in episode 15 of the 9th season of the TV show Supernatural.