Mutty the mussaurus is a major villain in The Star Pirates. He is second in command of the space pirate crew, next to their captain, Spiny Jim. Mussaurus are normally herbivorous dinosaurs but Mutty had sharpened his teeth into jagged fangs and thus became a carnivore. It is unknown why Mutty wanted to eat meat, but maybe he was lured to the crew by gold. He also wore a hook for a hand with a built-in communicator and peg legs.
This renegade ex-herbivore was among the first star pirates to board the astrosaurs' borrowed ship and tried to capture Teggs and Gipsy, but failed, and Spiny Jim caught the pair for them. It was also Mutty who sent Iggy and Gipsy the ransom message that the pirates would return Teggs and Gipsy in exchange for two A-wave Magnetrons. However, the slimy Mutty had no intention of keeping to his end of the deal. Mutty attacked Iggy and Arx in the Gold Magnet room with the Old Raptor and was defeated during a later battle there. It was Mutty who revealed that Spiny Jim's real name was not Jim, but was instead Gloria, after the pirate made one sly demand too many. However, it is debatable if the cunning pirate was telling the truth.
- Mutty is a Mussaurus patagonicus.