Slender Man/Film

Windigo
The Windigo is the titular main antagonist of the 2011 horror film Windigo. In this adaptation, the Windigo itself is an amalgammation of Slender Man and the Wendigo from Algonquian folklore. It is portrayed as highly sadistic and territorial, brainwashing and murdering any that dare venture into its territory.

Always Watching: A Marble Hornets Story
See here.

Slender Man (2018)
Slender Man serves as the titular main antagonist of the 2018 supernatural horror film of the same name by Sony Pictures. It is portrayed as a malevolent and demonic entity that psychologically tortures its victims before kidnapping them and fusing them with the trees in its forest.

It was played by Javier Botet.