A giant prehistoric praying mantis, recently freed from the Arctic ice, voraciously preys on American military at the DEW Line and works its way south.

Craig Stevens
as Col. Joe Parkman

William Hopper
as Dr. Nedrick 'Ned' Jackson

Alix Talton
as Marge Blaine

Donald Randolph
as Gen. Mark Ford

Florenz Ames
as Prof. Anton Gunther

Paul Smith
as Corporal

Paul Campbell
as Lt. Fred Pizar

Pat Conway
as Sgt. Pete Allen

Phil Harvey
as Lou

Helen Jay
as Mrs. Farley