Fishwife Mutant appears only in the original TimeSplitters as the sole female mutant of the entire series, if Nikki and Jinki are excluded. Her face is heavily mutated and her skin has a pale blue tone. She wears brown trousers and a white short-sleeved shirt under a pink top. She has a heavily mutated right arm, and her left arm is severely shrunken from the elbow down; she also possesses a third eye.
In a village in the 1950s, a cursed artifact that heavily mutated the inhabitants was discovered. It is the mission of two scientists, Doctor Seth Graven and Doctor Katje Nadir, to return this artifact for deeper research. However, the mutants seem to be against this, either by choice or via mind control. Only death will stop the mutants from trying to preserve the artifact hidden beneath the village.
Despite being a female character, she uses male character animations. This is also the case with most other non-human females in the original TimeSplitters, including Female Alien, Female Cyborg, and Girl Zombie.