Pazuzu

Pazuzu is a demon 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.

He is apparently bound to grant the Professor three wishes, though the reason is unknown. The wishes do not seem to be supernatural in nature, as he has only been shown to rescue the Professor from two desperate situations.

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 The Professor 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 if the show is renewed.
 * Though not named in the movie, Pazuzu was the name of the demon who possessed Linda Blair's character Regan MacNeil in 1973 film . A flashback early in the film shows Pazuzu as a half demon half animal, similar to how he appeared in Futurama.