Hamster Ernest Penfold is the assistant of top secret agent Danger Mouse. His own codename is the Jigsaw, because when he's faced with a problem, he goes to pieces.
Penfold was created by Brian Cosgrove and Mark Hall of Cosgrove/Hall Productions Ltd, and debuted in the cartoon Danger Mouse, episode 1 "Rogue Robots" on 28th September 1981. He was voiced by British comedian Terry Scott.
Always eager, easily surprised, often dense and frequently terrified, Penfold was a faithful sidekick and accompanied Danger Mouse on all his missions, including those on the printed page. Between May 1982 and November 1985 he appeared in Look-In Magazine's Danger Mouse comic strip, which was written by Angus P. Allan and drawn by Arthur Ranson. He also appeared in the six Danger Mouse Annuals.