Skunk

The giant catfish is an aquatic creature mutated from the common pre-War catfish.

Background
According to a California fisherman, in 2161, a three-eyed giant catfish he calls "Skunk" keeps scaring other fish away from his spot.

Appearances
The giant catfish is only mentioned in-game by a fisherman in Fallout. A humanoid, mutated catfish known as a "catfish mirelurk" also appears in The Art of Fallout 3, the art book available with the Collector's Edition of Fallout 3.