According to prosecutors, on Saturday morning, Morgan E. Geyser and Anissa E. Weier, both 12, from southeastern Wisconsin stabbed their 12-year-old friend 19 times.
One of the girls told detectives that they were trying to become "proxies" of Slender Man, a popular creepy internet meme regularly written about online.
During the attack, the girls only missed a major artery near their friend's heart by a millimeter, according to reports. The victim is currently in stable condition.
The two girls invited their friend over for a sleepover on Friday night and then lured her into the woods the next day and began their attack.
According to reports, the girls were planning the attack for months.
The "Slender Man" myth was started in 2009 on the website Something Awful. It was originally a game to insert creepy monsters into the backgrounds of photos.
It's gone on to inspire thousands of videos on YouTube and several video games. The idea is that he's a faceless man with tentacle arms who kidnaps children.
A passing cyclist who found the victim lying on the sidewalk called in the attack. If convicted, the 12-year-olds face up to 64 years in prison.
UPDATE: The creepypasta wiki page has released a statement about the attack. They've also an online fundraiser for the victim.
ALL WORKS PRESENTED ON THIS WIKI AND OTHER SITES (INCLUDING SLENDERMAN, JEFF THE KILLER, BEN, SONIC.EXE, ETC) ARE FICTIONAL STORIES AND CHARACTERS
Of course, only a small minority of people (mostly newcomers) on the wiki (and the Internet) truly believe what they read here. And for most people, they will not attempt replicate atrocities presented in some of the literature on the wiki. Something like this was bound to happen, considering the size of the Creepypasta community. All it takes is one person to do something insane and radical in the name of someone or something.
This is an isolated incident, and does not represent or attribute the Creepypasta community as a whole. This wiki does not endorse or advocate for the killing, worship, and otherwise replication of rituals of fictional works. There is a line of between fiction and reality, and it is up to you to realize where the line is. We are a literature site, not a crazy satanic cult.
There will be a feature film based on a Slender Man-related YouTube series called Marble Hornets. BuzzFeed has reached out to both the series' original creator and the feature film's production company.
Ryan Broderick is a senior reporter for BuzzFeed News and is based in New York City.