The man known as "Crease" was a member of Matty Square's gang. He had light hair and a lined face. He was bald and had an indentation in the top of his head.
When Burly and Jez were stunned by Moon Maid's paralyzing ray, Crease sneaked into the hospital where they were being treated. He disguised himself as a doctor and got Burly to explain to him what had happened. He then reported this to Matty Square.
Square made his own attempt to kill Moon Maid but was stunned. Crease helped transport Square back to their hideout.
Matty Square's next plan involved having Crease and Chuck (another member of the gang) drop a metal net over Moon Maid and then electrocute her to death. Square mis-wired the trap, though, and Crease and Chuck were killed.