Slenderman

In an inhuman being, he can reach 4cm in height, his arms and legs are very long, and he can stretch them to his advantage. He is thin, his skin is very pale, he has no face, he is always dressed in a black tuxedo, a white shirt, a black jacket and he can wear a red tie. And he has tentacles that come out of his back, which he cannot fully control. Making that when he does not have total control, he makes a mess around him.

He can become very serious, cold and manipulative, he can present himself to the most vulnerable people (children) as someone friendly, to then attract them and gain their trust to use them in his experiments.
He is not a nice person, very possessive, calculating, sinister, self-centered and more.

Thanks to its appearance, it is easy to hide among the trees, and to catch its victim easily.

can enter your thoughts, even manipulate them.

communicate through telepathy.

He can teleport, making him appear or disappear quickly.

He has large tentacles on his back, which he cannot control very well. These can stretch and even have a life of their own (they only appear in moments where he may be very angry or even too stressed)

It is not known exactly what his likes or dislikes would be, but his dislikes could be the scientist who took away his humanity and gave him this form and his appearance.