Fifi is a hostile character encountered by Earthworm Jim in New Junk City, the first level of the original video game. The game manuals describe Fifi as the rabid female pet poodle-bulldog of the owner of the giant junkyard, Chuck, who is also the boss at the end of the level. Fifi is described as a "psychotic, four-legged chainsaw with a rusty chain."
However, a dozen different Fifis are actually encountered and fought by Earthworm Jim throughout the level, so it is possible that they are all part of the same rabid litter. Fifis are actually the second most common type of enemy in the level, the most common being Crows.
Fifi will attack by running straight at Jim, pulling him down off wires and ledges, or jumping up and biting and mauling his super suit. Helpfully, Fifi will hemorrhage atom balls when taking damage. When killed, Fifi will whimper and explode, causing eyeballs and bones to fly everywhere.
- Chuck and Fifi were apparently defeated for good in the game, since neither one appears in the sequels unlike other villains in the game, nor do they appear in the animated television series or the toy line.