
A scientist develops a formula which will cause animals to regress to the form of their primitive ancestors, and tries it on himself with disastrous results.

as Prof. Clifford Groves

as Dr. Ross Harkness

as Jan Groves

as Ruth Marshall

as Game Warden George Oakes

as Celia

as Nola Mason, bar waitress

as Sheriff Andy Andrews

as Charlie Webb, bar owner

as Mr. Wheeler, hunter

as Danny, a townsman

as Buck Hastings, a townsman

as Jim Newcomb, a townsman

as Skeptical Naturalist

as Naturalists' Conference Chairman

as Dr. Fairchild

as Thickset Townsman at Webb's Cafe

as State Trooper Dispatcher