One of the few Special Corp members not taken from the criminal fraternity, he is a boffin who had developed a Time Helix device permitting time travel as well as a portal to alternate realities. He also has a great deal of general scientific knowledge, and sent a copy of his mind with the Rat on his excursion to the 20th century to enable Jim to build a time helix and return to his native time. Coypu is rarely described, apart from having prominent buck teeth - a trait he shares with his namesake, the Coypu, or nutria.