Guest Stars Robert Duvall as Louis Mace Howard Caine as Leon Chambers William O'Connell as The Creature Douglas Henderson as Dr. Tillyard Henry Brandon as General Crawford Uncredited Bob Johnson voices Loudspeaker Person Bob Johnson voices Chopper Pilot Vic Perrin voices Soldier Roy Jenson as Gunman Dean Smith as Second Creature Christopher Riordan as Young Doctor Roy Olvera as Mexican Guitarist
