Madison White

Madison White was the girlfriend of Kyle Glendower. While never making an appearance on-screen, she was mentioned by Kyle in Post-Halloween Footage. She is chronologically the first character who had began seeing the Slender Man, presumably. She was eventually killed and cannibalized by Clowny, becoming his first known victim.

Known Story
It's unknown how long Kyle and Madison were dating, only that David hadn't heard of her until Halloween. She had started seeing the Slender Man at some point, and told Kyle. Kyle didn't believe her at first, but then he began seeing him too. Shortly after he began seeing the Slender Man, Kyle hadn't heard from Madison. On November 3rd 2014, an unknown assailant contacted Kyle saying he had answers about Madison at Victor Park. Instead, Kyle wanders into a trap where he is chased by the Slender Man. He obtains a note referring to Madison, saying "She can't be helped now", with a symbol of a face with x's in the eyes

Later that night, Kyle is contacted by the unknown assailant via phone. He demands to be told what the assailant did to Madison, but receives no answer. Kyle grabs a knife and sets out to find the assailant, but is instead met with the Slender Man himself. Kyle tries to attack him, but is transported away, and after this point, he goes missing and turns up again as Sage. Madison's whereabouts and status are left unknown after this.

Sometime in May 2015, Madison White's remains were found in a ditch. Her body was partially cannibalized and mutilated. While Clowny has the Ask.fm account hacked, he answers a random question with "WH1T3 M34T", along with a gif of bloody hands. He is later shown butchering and cannibalizing Chance's body.

Theories

 * Madison may have been the catalyst for the events of TalesFromTheSpidersWeb, considering she had begun seeing Slender Man before Kyle. After Kyle began seeing him as of October 23rd, 2014, David has said he began seeing him around Halloween 2014, then Jesse began seeing him as of "Home Intruder", and later Simon in "V1S1T".