The Incredible Melting Man (1977)

"You've never seen anything til you've seen the Sun through the rings of Saturn," exclaims Alex Rebar. Apparently, somehow this causes him to start melting and eating people, such as a nurse in the tightest fitting nurse's outfit ever, a nerdy fisherman, a horny old couple who simply can't keep their hands off each other in a car. To save the day comes Doctor Ted Nelson!