The Devil's Rain (1975)
The same year Welcome Back, Kotter began, Travolta got his face melted (but the chin cleft's thankfully intact) in this B-movie, which featured a genius cast William Shatner! Ernest Borgnine! Tom Skerritt! and a plot about satanists.
Image Credit: The Devil's Rain: Everett Collection
Everybody's gotta start somewhere... Check out a few pre-fame victims of Jason, Freddy, Michael Myers, Leatherface, the Leprechaun, and killer tomatoes