The mutant fish was one of the various sea creature mutants genetically altered by Dr. M.
It shared similarities in appearance with an angler fish and was equipped with laser generators, tentacles, claws, underwater bombs and suction force. Dr. M installed a device in which he would be able to monitor the mutant's actions through interface. The mutant was deployed against Dimitri Lousteau during his efforts to retrieve Sly's cane when it was lost within the underwater caves of Kaine Island. Dimitri defeated the beast, but Dr. M still got away with Sly Cooper's cane.