Think about it, Shrek is very similar to Slendy. He has layers, he can teleport, he has proxies (Donkey and Puss), and he has unrealistic powers (4chan Shrek). In the game Shrek Simulator, Shrek behaves similarly to that of Slenderman. He can teleport, he stalks people in the woods, and he tries to stop people from stealing his onions (the pages). I believe that Shrek is related to Slenderman, either a rogue proxy, his cousin, a part of his species, or some other reason. I personally believe that Slender Man goes into the forest to hide from Shruk, and his magnificent onions.
was satire btw