Slenderman is a fictional character made famous by the 2012 horror video game Slender: The Eight Pages, although the myth of Slenderman actually emerged as an internet meme created by a Something Awful forum user named Eric Knudsen in 2009. Players believe that Slenderman can be found in Grand Theft Auto: Vice City, Grand Theft Auto: San Andreas and Grand Theft Auto V.
Slenderman is said to be commonly located somewhere in the country, possibly in Whetstone, or in Shady Creeks. Slenderman is believed to be able to teleport wherever he wants using special supernatural powers. In the video game Slenderman: The Eight Pages, the player has to wander through a thick forest to search for eight pages, while Slenderman continuously follows him. Slenderman also hunts the player in the sequel, Slender:The Arrival.
However, the Slenderman myth was created in 2009, five years after Grand Theft Auto: San Andreas was released in 2004, making this myth very unlikely. However, this myth is popularly believed to be revived from sightings of supposedly Slenderman dating back to 1600's up until the present day.
Influenced from GTA San Andreas, players modified GTA Vice City and included a fabricated Slenderman in the game that can be witnessed in the Haunted Mansion. The myth also returned in GTA V. Players claimed that an odd transparent thing appears in the bushes at night in Great Chaparral, but most of the evidence are PhotoShopped, even though GTA V was released 4 years after Slenderman myths were created, which makes it more believable.
In GTA San Andreas, Slenderman reports are commonly filed at the Blueberry Acres farm. However, this is most likely a misidentification of a door with a light on top located on the nearby Fleschberg Brewery.
However, Slenderman being in GTA V is impossible for legal reasons, as the character and its games are copyrighted, and Rockstar could be sued by the creators of the games and character.