Sorry, ist halt auf Englisch. Hoffe du verstehst es:

Slenderman or Slender Man is a creepypasta meme and urban-legend fakelore tale created on June 8, 2009 by user Victor Surge on Something Awful as part of a contest to edit photographs to contain "supernatural" entities and then pass them off as legitimate on paranormal forums. The Slenderman gained prominence as a frightening malevolent entity: a tall thin man wearing a suit and lacking a face with "his" head only being blank, white, and featureless. After the initial creation, numerous stories and videos were created by fans of the character. Slenderman was later adapted into a video game in 2012 and became more widely known. - Wikipedia.

Er ist also bestimmt nicht echt, sondern nur ein Internetphänomen. Keine Angst ;)