The Earth is invaded by alien parasites—AKA 'slugs'—that ride on people's backs and control their minds.
Donald Sutherland
Andrew Nivens
Eric Thal
Sam Nivens
Julie Warner
Mary Sefton
Keith David
Alex Holland
Will Patton
Dr. Lawrence Graves
Richard Belzer
Neil Jarvis
Tom Mason
President Douglas
Yaphet Kotto
Ressler
Gerry Bamman
Viscott
Sam Anderson
Culbertson
J. Patrick McCormack
Gidding
Marshall Bell
General Morgan
Nicholas Cascone
Greenberg
Bruce Jarchow
Barnes
Benjamin Mouton
Higgins
Donna Garrett
Miss Haines
Andrew Robinson
Hawthorne
Bill Blair
Slugged Businessman (uncredited)