When a traveling Wild West show comes to town, the natives are frightened by a one-foot-tall horse that is believed to be a bad omen. The superstitious natives try to return the horse to The Valley of Gwangi to avert disaster. Tuck (James Franciscus) and T.J. (Gila Golan) try to help archaeologist Bromley (James Naismith) find the tiny equine in the valley, but they unleash a prehistoric giant monster in the process in this implausible adventure feature.