The Monster of Camp Sunshine or How I Learned to Stop Worrying and Love Nature
A scientist carelessly dumps some toxic waste into a river. The gardener at a nudist camp drinks the water, turns into a monster and attacks all the (female) nudists.
Night of the Day of the Dawn of the Son of the Bride of the Return of the Revenge of the Terror of the Attack of the Evil, Mutant, Alien, Flesh Eating, Hellbound, Zombified Living Dead Part 2