The Slender Man is a creature or being with various nebulously defined characteristics and abilities. Slender Man was first mentioned in Something Awful Forum's "Create Paranormal Images". Slender Man generally appears (in modern times) as a tall man in a black or grey suit, red or black tie, and white shirt, with no eyes, mouth, or clearly defined facial features. It has no hair, and generally has normal-looking bare hands. Slenderman typically is depicted in imagery and literature as between 6 and 15 feet tall, depending on the situation, and in video as around 6-7 feet tall. Because of its inexact nature, and differences between series, no one has yet determined what it is. Currently, the two leading theories as to what the Slenderman may be are the Tulpa Effect and Quantum Theory.
In almost every description Slenderman's basic attributes will vary greatly, however several basic traits are typical of his behavior. He is shown to behave in a very passive aggressive manner, stalking targets for years at a time, torturing his target mentally for various unknown reasons. He is rarely ever shown in a benevolent light and is typically shown as a malevolent force. This behavioral pattern has an uncertain reasoning behind it, and exactly why he behaves in such a way has yet to be fully ascertained.
Slenderman's appearance provokes a wide range of responses, the most common being fear. This is partially due to his extremely towering size over a full grown adult, which mimics the childhood fear of adult humans bigger than the child. His behavior also factors into it. Finally, the main fact is he is completely unable to be described in human terms. While a description in words can be given, human language lacks the ability to truly define the entity until such a time as when humans can interact with him (if at all possible). This problem stems from the fact that he operates in a plane of existence further from humans. This is believed to be fourth dimensional space which gives him powers a human cannot understand due to humans living in three dimensions of space and being unable to comprehend the fourth dimension at this time.
Slender: The Eight Pages is a free indie-developed video game released in June 2012 as a beta for Microsoft Windows and OS X, utilising the Unity engine. The game is based on the Something Awful forums' creation, Slender Man
Slenderman's original abilities included invisibility to select people, adult humans, or anyone without use of a camera, the ability to change height and body shape, the ability to shape its arms into tentacles, and the ability to sprout tentacle-like appendages from its back and shoulders to be used as additional arms or legs (or simply to instill fear into its prey). Many stories seem to indicate that it can control a person's mind, which became the basis for the Proxies in the video ARGs, a trend that would later spread to Slenderblogs. Slender Man also had connections to children, with many of the original stories revolving around disappearing children or featured Slender Man being sighted in photos with children.
