Bongo

Bongo is a one-eared rabbit from Matt Groening's . On Futurama, he appeared in Joe's Ark Pet Store as an animal being sold by the pet store clerk. In Bender's Big Score, Santa Claus' aides made toys resembling him, so is presumably somewhat famous in the Futurama. Along with, he also has a cameo in "Simpsorama", where he writes on the wall, "Crossovers are hell", both in reference to the name of his comic strip and lampshading the fact that the episode is a crossover.

Trivia

 * Bongo was originally from Life in Hell, and is a major character in that universe.