He is pale, completely faceless (unlike Splendy) and wears a black suit with a tie. He's also very slender, as his name implies.
Slendy is all about being big and scary, which often worries Splendorman. He's got these things called "Proxies" that envy the Buddys, because proxies aren't treated very kindly by Slenderman. Splendorman doesn't understand why people would want to be proxies.
Slendy likes to pretend his relatives don't exist and stuff, which makes Splendy very sad, but at the same time, Splendy is somewhat relieved due to Slendy's violent tendencies.
- Slendy actually had a dog named Rocky once. Slenderman had trouble taking care of it, so Splendy took it in. Poor Rocky passed away, but he had so much fun playing frisbee with Tiffany and Becky. He liked to sit on Splendy's lap.
- Slendy hates vibrant colors, so that's why he always wears black.
- Slendy doesn't like tic tac toe, he always tells Splendy the X's are supposed to go on the O's, which is very confusing.