Pazuzu

Pazuzu is a gargoyle who Professor Farnsworth owned and put through college. Pazuzu escaped and due to Farnsworth's senility he could not be found. However it is later revealed that he was hiding on a wing of the Planet Express ship and when Farnsworth was drowning in the Fountain of Aging, Pazuzu saved him and in reward Farnsworth granted him freedom. Pazuzu moved to Paris and had a son who he told his story of freedom to.

Trivia

 * Can apparently speak French, which is understood to be a dead language by the year 3000.
 * Named after Pazuzu, who in Assyrian and Babylonian mythology, was the king of the demons of the wind.
 * In The Beast with a Billion Backs, Pazuzu said Farnsworth still had one wish left (the first was possibly to escape the Fountain of Aging, and the second to escape from prison), which means it's possible that he may come back in another movie.