Marlon Harold Hatter is Matt's pet mini Trandoshan devil that loves to drive a toy car and his favorite food is popcorn and candy. He is usually doing Matt's work or just sleeping in while Matt is at the Multiverse booking bad guys. He is the only one in Matt family to know about the Hater Hero stuff and tell him whenever Roxie is calling him.
Marlon could be described as a little dramatic and highly-strung, he panics and he definitely overreacts. He loves Matt and you'll always find him by his side or perched on his shoulder but Marlon does get a little annoyed that Matt puts him in some difficult situations. Marlon uses "Chitterspeak", a mixture of squeaks and squeals, to communicate with Matt.