Cardinal Richelieu serves as the primary antagonist across the Dogtanian franchise, appearing in the 1981 animated series, the 1985 television film *Dogtanian: Special*, the 1989 sequel *The Return of Dogtanian*, the 1995 film compilation *Dogtanian: One For All and All For One*, and the 2021 CGI feature *Dogtanian and the Three Muskehounds*. Depicted as an anthropomorphic Dobermann Pinscher, his visual design features aggressive, angular traits contrasting the heroic characters. He possesses a crafty, scheming, and intimidating personality and is typically accompanied by a pet raven.

As chief minister to King Louis XIII, Richelieu wields significant political influence, rivaling both the king and Monsieur de Tréville, captain of the Musketeers. His schemes consistently aim to undermine the monarchy and consolidate his personal power. He commands a network of agents: Count Rochefort (his primary henchdog with floppy ears), the cat spy Milady de Winter, the cowardly mastiff captain of the Cardinal's Guards, Widimer, and Marco, a rat initially manipulated into working against the Musketeers. His enforcers, the Cardinal's Guards—a cowardly rabble of various animal breeds including pigs—rival the Musketeers.

Richelieu employs strategies of espionage, kidnapping, and assassination. He orchestrates the kidnapping of Queen Anne's maid, Juliette, to exploit her connection to the queen. He later collaborates with the Duke of Buckingham to destabilize France, though this alliance is ultimately foiled. His manipulation extends to using Marco for covert operations, though Marco eventually defects. Across all media, Richelieu remains a persistent threat whose plans are consistently thwarted by Dogtanian and the Muskehounds. His character undergoes no significant redemption, enduring as a symbol of ruthless political ambition throughout the franchise.