The Four-Legged Mimic was an shapeshifting animal on Vergon 6. It mimicked Leela's appearance so that Fry would throw the net over Leela. It was then eaten by Nibbler when all the animals were on the Planet Express ship.
The Four-Legged Mimic looked somewhat similar to Leegola in Bender's Game, which is Leela as a centaur. In the ship, the Four-Legged Mimic changed its appearance to resemble Nibbler.