Hey, just found it. You're actually pretty close. Onepagearticles.com mentions that there is a story about a man that is similar to Slenderman, only his name translates to 'Rough Man', 'Tall Man', or 'Gross Man' from his German name and is a tale to get children to behave and go to bed when they should, or he'd come and snatch them away. Kind of a gruesome tale, but then again, each culture has different stories and legends.
Yeah and you know what the crazy thing is? Slenderman wasn't a murder or that. The original creator didn't think of him that way. It's just how some have interpreted him because of how he looks. Personally, I think the tales of Slenderman helping children or being friends with humans is better, especially ones with Splendorman.
Is it? Wikipedia mentioned it was a character that was created for internet stories, although the stories of Slenderman vary from him being a murderer who eats children and adults to just a creature who lives in the woods but doesn't eat children. From this idea sprung other such Creepypasta like Laughing Jack, Offender Man, Ticci Tobi, and Happypastas like Splendorman. To be honest, I really don't know, but a German tale? I'll have to check that out.
Hey! I really like your Dr. Seuss Slender artwork. You should make a Dr. Seuss version of Dragon Ball Z, Sailor Moon, Hetalia ,Lucky Star,& Pokemon Indigo League. Because I'm really excited to see anime in Dr.Seuss form. But be sure there are bright colors & the characters' skin are white as snow. Thank You!!!.