|“||I am the Anti-Body. I was supposed to stop the spread of the infection. But I couldn't. I was... Too weak. Too human. In order to... Hault... The infection's consumption in all of us... We need to spread the infection to others. Like... Carriers of a virus, in a way. While it did alleviate some of our problems... It didn't help everything. It was a mistake. I couldn't do what needed to be done, to stop the infection. And what was that? To destroy all carriers.||„|
|~ The Anti-Body|
The Anti-Body first appeared in Three, as he is seen running through the field behind the three protagonists, Avery, Ellie, and Macy. He is frequently seen stalking the girls in the background throughout a portion of the series.
While the girls are held up in Ellie's cabin, the Anti-Body appears in there, and when he's about to kill Macy, Avery attacks him and rips off his mask.
He starts ranting about "The Infection", and how he "must stop it" (referring to the Slender Man's targets.) He starts screaming at Ellie about how she has spread it through the Internet by uploading her videos, and he then explains to them that the whole world would be infected if they didn't stop uploading.
The Anti-Body then begins coughing blood, screaming and crying that "he thinks too much." He is then seen some time later in the car with the girls. He is later seen holed up with Avery and Ellie sometime later. They appear to become allied after this.
Later, it is revealed that there are, in fact, an entire group of people that the Anti-Body was formerly aligned with hunting the protagonists. While Ellie is camped out by herself, the anti-Body gives her a gun for self-defense. The next day, they try to talk to her again, where she becomes deranged and contemplates suicide. The Slender Man shows up, and Ellie attempts to shoot it, while somehow accidentally killing the Anti-Body as a result.