He 's the Internet 's own monster , a ghoul who lurks in its darkest corners and , like the Web itself , has mutated time and again to suit the dreams and desires of his devotees . He is Slenderman , a menacing , faceless specter in a dark suit -- sometimes portrayed with octopus-like tentacles -- known to haunt children and those who seek to expose him . He was born in 2009 in an online forum for people who enjoy creating fake supernatural images . And , on Saturday , police say , he played a role in the attempted murder of a 12-year-old girl in suburban Milwaukee by two female classmates who stabbed her 19 times . According to police , the girls said the attack was meant to impress the fictitious bogeyman . To be clear , the origin story of the monstrous character ( sometimes referred to as The Slender Man ) in no way urged readers to kill to earn his favor . But Slenderman has undergone hundreds of permutations online in his five-year existence . In June 2009 , a Photoshop contest for images that appeared to be paranormal was launched in a forum on the website Something Awful . According to Know Your Meme , a blog that chronicles Web culture , the goal of the contest was to create the images and then use them to fool , or `` troll , '' other Web users by submitting them to paranormal websites . Site member Eric Knudsen ( under the screen name `` Victor Surge '' ) submitted two images to the contest , both black-and-white images of children , one of which appeared to show a largely undefined figure lurking in the background . They were presented as being from 1984 , and one included the text `` 'We did n't want to go , we did n't want to kill them , but its persistent silence and outstretched arms horrified and comforted us at the same time ... ' -- 1983 , photographer unknown , presumed dead . '' ( Know Your Meme has documented these posts , although links to the original thread no longer work . ) A day later , according to Know Your Meme , Knudsen added a third photo and a fictional doctor 's account of a mass killing . And , from there , Slenderman 's assault on the Internet began . `` Some people joked in the thread , 'Would n't it be funny if some of these ended up on those paranormal websites or someone said these pictures look real , ' `` Knudsen said in an interview this year with WNYC 's `` TLDR '' podcast . `` But I do n't think anyone really expected that to happen . '' Other Something Awful users began creating their own Slenderman stories . And they spread to other sites . Over the past five years , he 's appeared in fan art , short stories , videos , video games and other media all over the Web . A Google search for `` Slenderman '' on Tuesday returned more than 4 million results . `` Marble Hornets '' is one of the most popular permutations . It 's a video series on YouTube , presented in `` Blair Witch Project '' -like faux-documentary style , with nearly 380,000 subscribers . Slenderman has also been a popular subject of `` creepypasta , '' a form of Web-based short fiction . A play on the term `` copypasta , '' which itself is derived from the keyboard action `` copy-paste , '' creepypasta is horror fiction written with the Web in mind and , often , done in a style that makes it appear like a news item or other piece of true crime . The girls accused in the Milwaukee stabbing told police they knew the character from the Creepypasta Wiki , a site that compiles such fiction . The site has issued a statement condemning the attack . `` This is an isolated incident , and does ( not ) represent ... the Creepypasta community as a whole , '' the statement reads . `` This wiki does not endorse or advocate for 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 satanic cult . '' Knudsen , too , has lamented losing control of his creation . `` I feel like less of a creator and more of an administrator , in a lot of respects , or the manager , '' he told NPR in the interview from January . Knudsen , who could not be immediately reached for comment , has filed for a copyright on the character . `` I feel like I 'm Slenderman 's manager , and he 's out there doing his thing , and I need to just kind of watch him and take care of him . '' When can kids understand reality vs. fantasy ?
`` Slenderman '' character allegedly inspired 12-year-old girls to stab a classmate . Slenderman was born in 2009 in an online forum for people who create fake supernatural images . He 's appeared in fan art , short stories , videos , video games on Web . Police : The girl stabbed the boy with a knife and he died of his injuries later that day.