The Slender Man is a supposed paranormal creature, invented as the result of a photoshop contest on a forum on the Something Awful Web site. The creature captured the imagination of many people who saw the pictures on the internet, who then went on to write creepypasta (stories intended to be shared online) about the Slender Man, create pictures, and even develop independent video games about the character.
Origins of the Slender Man
In June 2009, the Something Awful Forums held a paranormal photoshop contest, requiring participants to create creepy-looking alterations to normal photographs, and then pass them off as real in paranormal forums.
One such entry contained two black and white photographs of groups of children, with the creature that would be known as Slender Man photoshopped into the background. User Victor Surge submitted these two photos along with a fabricated witness account of the creature called Slender Man. The thread began to grow with more and more photographs and stories, until the legend of the Slender Man reached Internet meme status.
The Slender Man's appearance
The Slender Man is depicted as an extremely tall, thin man, wearing a black suit. His face is blank of any features, extremely pale, and almost appears to be wrapped in bandages or cloth. When he is not wearing a hat, his head appears to be bald, but he sometimes wears a bowler, fedora or top hat. He has between four and eight long, tentacle-like appendages which protrude from his back, and some accounts state he can lengthen and shorten them at his will.
The Slender Man's behavior
Although he originated being photoshopped in the background of photographs, much of the spookiness about the Slender Man involves the air of mystery that surrounds him. It is hard to say what his motivations are, despite the fact that most creepypasta stories claim he kills children almost exclusively.
He is usually reported to be found in wooded areas of suburban neighborhoods, and photographs have shown him among large groups of children.
According to legend, the Slender Man seems to enjoy psychologically torturing his victims, and will begin stalking people who become scared of his existence. He is believed to purposely give these victims small glances of him to keep them in a state of paranoia.
Depending on the myth or source, simply catching a glimpse of the Slender Man in person is enough to cause terrible effects to the observer. It can create a hypnotic trance rendering a person unable to move, or in more minor cases, may just cause memory loss, insomnia, coughing fits or visual distortions. Some accounts also state that when he opens his tentacles in an outstretched pose, victims become helpless and can not help themselves from walking into them.
The Slender Man is nothing but a figment of some powerful imaginations, but the stories and pictures are fun and creepy enough that they are a treat to share with friends. Just don't look directly into his blank face, and you should be fine.