A social misfit, Willard is made fun of by his co-workers, and squeezed out of the company started by his deceased father by his boss. His only friends are a couple of rats he raised at home, Ben and Socrates. However, when one of them is killed at work, he goes on a rampage using his rats to attack those who have been tormenting him.
Bruce Davison
as Willard Stiles
Ernest Borgnine
as Al Martin
Sondra Locke
as Joan Simms
Elsa Lanchester
as Henrietta Stiles
Michael Dante
as Brandt
Jody Gilbert
as Charlotte Stassen
William Hansen
as Barskin
John Myhers
as Carlson
J. Pat O'Malley
as Jonathan Farley
Joan Shawlee
as Alice Rickles
Almira Sessions
as Carrie Smith
Pauline Drake
as Ida Stassen
