Slender Man

The Slender Man was created on 10 June 2009 by Something Awful forum user Eric Knudsen (pseudonym Victor Surge) during a Photoshop contest; Knudsen posted two black-and-white images of groups of children altered to include a tall, thin spectral figure in a black suit, accompanied by short fictional witness captions. The figure was then expanded collaboratively by many users across forums, videos, games, and other media to form a mutable, open-source mythos rather than arising from an established traditional cosmology.

Common portrayals show an extremely tall, unnaturally thin humanoid with pale white skin and a featureless or blank face, dressed in a black suit and tie. Many depictions add very long, tentacle-like arms or branching tendrils sometimes emerging from the back; early images and fan works often render him in black-and-white or photographic montage styles. Exact facial detail, appendages, and other attributes vary across authors and media.

Across the collaborative fiction the Slender Man is recurrently depicted as stalking and observing people (frequently children or young adults), abducting children, causing rapid-onset psychological symptoms ('Slender sickness'—paranoia, nightmares, nosebleeds), and sometimes converting or influencing humans into proxies. Specific abilities commonly attributed in various works include extending tentacle-like arms, teleportation, and interference with recording devices and screens (notably popularized by the Marble Hornets web series). These abilities and behaviors are not canonical and vary by author and medium; many retellings intentionally leave motives and ontological status vague.