Help ID a movie...

Another thread about drive-ins made me think of a horror film I saw, released in the 70s. Unsure, but think it was a US production. Takes place in a small seaside town. Story is essentially town gets taken over by evil after some being emerges from sea. Includes scary albino dude who eats a rat's head while driving a tow truck; young woman attempts to flee, only to encounter townsfolk in supermarket eating raw meat--they attack her; another young woman goes to movies, only to have audience all turn to stare at her--they also attack her; man working on car in shop has lift brought down to crush his head. Phrase something along the lines of "They're out tonight" & afflicted people wind up with blood dripping from their eyes.

Can't remember any title, actor, writer, director information that would help me to find it on IMDB or Amazon.

Saw it while in high school with friend, who was so freaked out that all you had to do was recite that phrase to him in a weird voice & he'd run for cover.

Any ideas?