According to the official Slender Man page on creepypasta.wikia.com (the website where Geyser and Weier first discovered Slender Man), Slender Man is “an alleged paranormal figure purported to have been in existence for centuries, covering a large geographic area. Believers in the Slender Man tie his appearances in with many other legends around the world, including; Fear Dubh (or, The Dark Man) in Scotland, the Dutch Takkenmann (Branch Man), and the German legend of Der Großmann or Der Grosse Mann (the Tall Man)” (creepypasta.wikia.com). Also according to the wiki, Slender Man is described as “a being (male in appearance) who looks like a man with extremely long, slender arms and legs. He also appears to have 4 to 8 long, black tentacles that protrude from his back […] He is described as wearing a black suit strikingly similar to the visage of the notorious Men In Black, and as the name suggests, appears very thin and able to stretch his limbs and torso to inhuman lengths in order to induce fear and ensnare his prey”
According to the official Slender Man page on creepypasta.wikia.com (the website where Geyser and Weier first discovered Slender Man), Slender Man is “an alleged paranormal figure purported to have been in existence for centuries, covering a large geographic area. Believers in the Slender Man tie his appearances in with many other legends around the world, including; Fear Dubh (or, The Dark Man) in Scotland, the Dutch Takkenmann (Branch Man), and the German legend of Der Großmann or Der Grosse Mann (the Tall Man)” (creepypasta.wikia.com). Also according to the wiki, Slender Man is described as “a being (male in appearance) who looks like a man with extremely long, slender arms and legs. He also appears to have 4 to 8 long, black tentacles that protrude from his back […] He is described as wearing a black suit strikingly similar to the visage of the notorious Men In Black, and as the name suggests, appears very thin and able to stretch his limbs and torso to inhuman lengths in order to induce fear and ensnare his prey”