Grampus is a midget submarine, who was once owned by the navy. He is a grandfatherly figure and a close friend of the Star Fleet, and has helped them out in various situations.
Grampus appeared for the first time in Pirate, in which he helped to prove Ten Cents' innocence. In Regatta, he was nearly blown up by Bluenose the naval tug having been branded as 'too old' for further service. He speaks with a Central English accent (with a noticeable lisp).
In Regatta, he also saved Lillie Lightship from sinking by plugging the hole in her side with his head. He was thankfully swiftly rescued by the Star Fleet. On the same day, he was bought by Captain Star and joined the Star Tugs as their first star submarine.
Grampus also has a tendency to blow water in the tug's faces (mostly at Bluenose).