A determined, yet occasionally eccentric seafaring hamster, Captain Hamstern follows in the paw-steps of his father and his grandfather, who were also pirates. However, he is not necessarily a "bad" hamster; he is actually fair and just, and realizes when he has misjudged or made a mistake.
In the Hamtaro: Ham Ham Grand Prix - The Miracle of Aurora Valley, he kidnapped Bijou with his crew as a way to prevent the Snow-Hams from praying for snow. Despite being kidnapped, Bijou was very hospitable and friendly to the pirates and Captain Hamstern even wanted her to join the crew. He eventually releases Bijou after letting Hamtaro defeat him in the Grand Prix, realizing he had been irrational in taking her away.
See also: Captain Hamstern/Gallery