Slender Man/Webseries

Marble Hornets franchise
Marble Hornets is a YouTube-based horror webseries based on the Slender Man mythos. It consists of the original series Marble Hornets which ran from 2009 to 2014, its 2015 VOD feature film Always Watching: A Marble Hornets Story, its first sequel series Clear Lakes 44 which ran from 2015 to 2016, and its second sequel series ECKVA, which began in 2017 and is ongoing.

In the Marble Hornets continuity, the Slender Man is portrayed as The Operator, an enigmatic entity that stalks the characters and uses mind control and insanity inducement to torture and kill victims or transform them into Proxies in its service, such as Hoody and Masky. The Marble Hornets depiction of the Operator came about before the contemporary mythos, and is wildly credited with helping to shape the Slender Man mythos.

EverymanHYBRID
Slender Man appears as the secondary antagonist of the webseries EverymanHYBRID, being an occasional ally and even rival of the main antagonist HABIT. He stalks the main characters and uses its psychic powers and emission of Sigma Radiation to drive its victims insane and have them carry out its dirty work. This Slender Man also is known to take the victims it captures (especially children) and gut them, place them in bags, and suspend them from tree branches.

Animeme
Slender Man appears as a recurring character in the YouTube-based animated comedy webseries Animeme, which features shorts with characters from internet memes and fads. Slender Man appeared in several episodes as one of the villainous memes, and went up against both Insanity Wolf and the Unwanted House Guest in the miniseries Animeme Rap Battles.

Annoying Orange
Slender Man appears in an episode of Annoying Orange, where Orange, Pear, Midget Apple, and the Bananas are in Slender: The Eight Pages looking for the pages to escape. Slender Man kills the Bananas and tries to kill Orange, but Orange hits it in the head with a paper airplane. The two begin an argument as Orange tells Slender Man that it is not scary, and annoys it by asking it for wishes and/or gold after getting all of the pages. Slender Man, angry and annoyed, runs away with Orange following until Midget Apple hits it with a truck.

IN another episode, Orange and Midget Apple play Slender: The Arrival and end up losing. In 2018, an episode was released of Orange, Marshmallow, Pear, and Midget Apple riffing and making fun of the trailer for the upcoming film.