With no facial features at all, the Slender Man is a petrifying creature. Though not being guaranteed as an alien, the Slender Man is not human. He appears as a faceless humanoid creature wearing a black suit and tie, with stretchable limbs which terminate on tendrils. Once its arms are stretched it will hypnotize its victim, leaving him/her helpless. It is said to eat its victims afterwards, although nobody knows for sure. Other accounts report that it transforms some victims into heavy fog; others report it extracting and bagging their organs. No one knows the exact origins of the Slender Man, but it's often believed to be extraterrestrial and/or extradimensional. It can induce insanity, insomnia and loss of memory to its victims, and has the ability to teleport. It is usually described as about eight feet, but its tendrils can extend this height. Its skin color is light grey or white. Its usual habitats are foggy wooded areas. It usually stalks its prey and slowly drives them insane, causing them to hallucinate in nightmarish ways.
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. The internet popularity of Slenderman has spawned a massive amount of interconnected ARGs, collectively known as the Slender mythos
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.
The most important factor about Slenderman is the mystery. He lives unlike any human being despite having a similar appearance to one. It is uncertain if he is social, or even understands human languages or behaviors, nor why it is humans appear to be his main target. His targets will typically behave in off ways as if possessed (Proxy), but whether their psychosis is causing them to speak for him or for themselves isn't entirely certain either.
Slenderman's appearance is variable as the years go on, but as of to date the most recent appearance is that of an abnormally tall human with long arms and no face whom is wearing a business suit. Again it is uncertain if his suit is real cloth or some form of skin molded into such an appearance. If it is the former, this would imply an intelligent being attempting to try to blend in. If it is the latter, it shows a being whom is extremely adaptive and evolves to match his environment and stick out less (or more).
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.
In total two major types of Slender Man descriptions exist. The original versions depict him as not only malevolent, but extremely dangerous. He will do odd things such as removing organs and placing them in bags, impaling targets on trees, and aggressively stalking targets after a period of time. A contemporary depiction shows Slender Man as being extremely passive aggressive, often letting a person slowly delve into madness at their situation until being unable to cope. If invited to anger, he will typically charge a target down until caught and vanish with them to unknown locations. This version also shows an odd response to electronic equipment and causes massive problems with audio, surveillance, camera, and other various electronic devices with displays or audio. Sometimes an individual can determine if he is near simply by how certain electronics react such as radios, televisions, or cameras. How powerful this effect is seems to vary, and can either be due to Slender Man's own state of aggression, or other outside factors either inside or beyond Slender Man's control.