Denizens of the Marsh
Mutated local fauna include common North American muskrats, badgers and rabbits, birds, fish and snakes.  These native animals suffer from mutations due to prolonged exposure to the toxic chemicals present in the marsh lands.  Most are deformed, highly resistant to radioactivity, and entirely inedible to humans.  More alien inhabitants include giant leeches (SB4: CS Navy, p. 103), skull gulls, giant waterstriders (SB4: CS Navy, p. 111), and water serpents (SB4: CS Navy, p. 110).