Terry (voiced by Mike O'Gorman) is Leonard Powers's nemesis. He is released by Leonard's wand when it is knocked off into a bubble tub, by the mermaid who's having fun with Leonard, and water-damaged. Leonard tries to send his nemesis back to the evil realm but only manages to trap him in a large piece of paper, making him appear only in two-dimension.
Terry is happy to learn that Mark Lilly has accidentally "killed" Leonard by breaking his wand. When he and Twayne Boneraper see zombie Abraham Lincoln appears in Leonard's funeral, they decide to re-assassinate him.
Though he doesn't look much like a demon, he does share a barbed penis as discovered by the urinal. He also gets along with Twayne which could suggest he is one.
However, Leonard is not truly dead. But since all pieces of his flesh have not been put together when his remains regenerate, the pieces become hundreds of tiny Leonards. The babies die gradually and as each one dies, all the others grow a bit. When by the end only two little Leonards remain, one of them rushes to Lincoln's rescue and intercepts Terry's attack who has been folded into a paper plane and thrown by Twayne. The little Leonard dies but succeeds in preventing the assassination, and the remaining one becomes the original Leonard again. Terry is caught by special agents and Twayne escapes. Yet Terry manages to return to his evil realm again and is seen at the end in a TV drinking wine with Twayne across the screen.