Phosfins are predatory, 2' long fish that are equally at home in fresh- and saltwater environs.
When phosfins attack, they are so tenacious that a successful hit results in latching onto their target, automatically doing biting damage each successive round. Not content to hunt only beneath the waves, phosfins can leap up to 10' above the surface to grab water-side or flying prey...and when exposed to the air in this fashion, they burst into luminous flame, causing an additional 1d8 damage per round to those in contact. (Truly, being devoured by razor-sharp teeth while simultaneously roasting alive is one of the grislier fates in the Mutant Future.) The only way to extinguish this flame is to either return the phosfin—usually along with its victim—to the water, or kill the fish. Dead phosfins still burn for an additional 1d10 rounds after perishing.
Fishermen and waterborne traders dread phosfins, as one stray catch or errant leap can reduce a boat and its cargo to cinders; however, some pirates and warlords use them as living weapons.
Phosfins return annually to their spawning grounds, and migratory waterways and rivers blaze with the fury of hundreds (if not thousands) of leaping fish.
Mutations: Aberrant Form (Fiery Slime), Reflective Epidermis (Heat)