I'm just a newbie, but I thought I'd put my two cents in. As everyone else has mentioned, Slender man is not real. He was made up on message board during a contest. However, there have entities like slender man such as the banshee or the wendigo in mythology. I'm not trying to support the one who believe Slender man exists, this poor guy needs some serious help. Then again, there are always going to be people who say things are there when they really aren't.
Maybe this time next month there will be an army of Slender Men? Maybe Slender Man will meet a Slender Woman and have slender babies? You never know.
The OP is probably trying to convince you that he was taken by Slender man...
sorry i haven't been posting because i cant be posting so much to you guys because i have other things to do so this is probably gonna be my last post because i dont have time to pointlessly prove to skeptics that he's real so no this was not a troll goodbye for now