Face, Kevin Pie Face's Dad (voiced by Gary Martin) The Postman (voiced by John Baddeley) Like in the comic, the Postman is mostly harassed by Gnasher whenever he tries to deliver the mail to Dennis' House. Rasher is Dennis' pet pig that made a cameo in the episode Dennis and the Beanstalk. Sidney is Dennis' spider based on the comic book spider Dasher that with his web saved the day. Seen in Secret Agent Dennis. Walter's Dad (voiced by Gary Martin) School Headmaster (voiced by Colin McFarlane) Flossy Muggins (voiced by Sally Grace) is a wacky inventor who helped Dennis build some ingenious inventions. Seen in Revenge of the Robot. Dirk Cool, Secret Agent (voiced by Gary Martin) Seen in Special Agent Dennis. Aunt Beryl is Gran's sister. Hugo (voiced by Simon Callow) is the Colonel's adventurer cousin who helped Dennis and the others save Gnasher and other Abyssinian tripe hounds from the rat catchers. Seen in The Trial. Mr Smiley (voiced by Derek Nimmo) is a nutty psychiatrist, who tried Dennis like practical jokes on the parents during his course on "How to Understand Children", but couldn't get the better of Dennis even though the parents thought he was worse than him. Seen in Dennis and the Grown-Ups Slasher Brown (voiced by Denis Quilley) is Walter's twisted uncle, who runs the barbershop. Seen in Hair Today, Gone Tomorrow as the main antagonist. Reg Trademark (voiced by John Baddeley) is an eccentric inventor who makes insane and useless gadgets. He builds a shopping mall and uses subliminal messages to make the customers buy his on sale gadgets. Seen in Malled. Bertie Blenkinsop is a fellow softy and friend of Walter. Seen in Snowbound. Spotty Perkins is a fellow softy and friend of Walter. Seen in Snowbound. Captain Trout (voiced by Billy Connolly) is a sailor who enlists Dennis and the gang as the crew aboard his ship, the S.S. Rustbucket. Despite managing to capture the boys' interest when he relates to them how he lost his father, Captain Prefab to a whale known as Dopey Mick (a parody of Moby Dick) Captain Trout is essentially a strict, no-nonsense person - which results in Dennis very quickly losing all respect for him when he discovers this! However, he is grateful to the gang for their role in helping him be reunited with his father, and when they help him escape from