"No help... no chance... no escape!!!"
--Martin Landau, hamming it up right out of the stratosphere
"Without Warning" may be tough to find, but is well worth it. I'm just going to rattle off some names:
Greydon Clark!
Martin Landau!
Jack Palance!
David Caruso!
Cameron Mitchell!
..and Larry Storch as The Scout Master!
The last movie for Ralph ("Food of the Gods") Meeker and almost the last one for Neville ("Eaten Alive") Brand.
If you imagine "Predator" as a VERY episodic teen-slasher flick with the worst low-budget makeup FX possible, you have "Without Warning." The alien hunter flicks Frisbee-like tomato slices at its victims, which proceed to sprout hooks and fangs to kill with. (They cannot, however, cope with windshield "glass.") The alien then stashes the bodies in an old shack because his spaceship is just waaaaaay out of reach of the budgie.
Most of the victims are random idiots who perform little "plays" (the eternal father/son conflict straight out of "All In The Family," the ultra-dorky Scoutmaster stereotype) to eat up time before the killer tomato slices abruptly take them down.
Ultimately, the standard two-pairs-of-teens drives into the ugly scrub brush in which this movie takes place, and get caught between the alien hunter, Palance's nutjob alien-hunter hunter, and Landau's nutjob "Vietnam Vet" stereotype, complete with flashbacks. It's not pretty, but it's pretty funny.