First Appearance: Marvel Mystery Comics #4 (February 1940).
Golden Age Appearances: Marvel Mystery Comics #4-9.
Modern Appearances: None.
Years Active: 1940-?
The Ferret is a "well-known author and private investigator." He lives in Greenwich Village in New York City and is known for his "crime doesn't pay" articles. No other biographical information on him is given. No origin, either, so we never learn why he chose to become a private eye.
The Ferret has no superpowers, but he has a trained pet ferret who helps him solve crimes. He's a good detective, is good with his fists, and he wears a bulletproof vest. He needs the vest, because he is armed and will shoot criminals.