Casper

Casper, better known by his fan nickname, Trenchcoat, is an ambiguous figure in Forest of 4. He is a ghost, evidently from the 1920s, and was marked by the Slenderman during that time. He also has some familiarity with BJT. He claims that he wants to protect Wyatt.

The main line of communication with Casper is through his Tumblr account. For unknown reasons he only speaks in Morse code.