Slenderman

Slenderman appears as a very tall, pale man with unnaturally long, erratically bending limbs and, occasionally, black, flexible tentacles or appendages growing from his back. One of his most striking features is his complete lack of personality. Some characteristics of the image:
He wears a black funeral suit with a white shirt, which could lead one to mistake him for a government agent or one of the Men in Black.
He is able to teleport, lengthen his body and arms, change their number, and even turn them into tentacles.
When attempting to capture someone, he uses his hands, tentacles, or attempts to induce a stupor through hypnosis. An integral part of the Slenderman's image is the absolute uncertainty and obscurity of his intentions. The canonical version of his origin, nature, and purpose remains, paradoxically, a complete lack of it. That is, where he originated, whether he was someone else before, and why he abducts people are unknown, perhaps even to his creator. Some sources may offer various hypotheses, ranging from the plausible to the downright absurd, but it should be remembered that none of them constitute an official theory, as there simply isn't one. It is precisely this uncertainty that frightens people the most, as no one can say with certainty what the Slenderman does to his victim after abducting them. Furthermore, his inherent inevitability is also taken into account, making him akin to death, as it is impossible to resist him, and in most cases, the victim can only save themselves by fleeing.

Slenderman is believed to be an excellent telepath, due to the lack of most of his senses and, consequently, a hypertrophied sixth sense, and in Marble Hornets, he was credited with the ability to erase, edit human memory, and manipulate people, turning them into puppets.