It's a western! No, wait...it's a prehistoric monster movie! No, wait...it's both! It's "The Beast of Hollow Mountain," in which an American cowpoke (Guy Madison) goes up against a (stop-motion) dinosaur who's stomping around his ranch in Mexico eating all the cattle. Later remade as "The Valley of Gwangi," this rootin'-tootin' thriller co-stars Patricia Medina, Carlos Rivas. Next, in an effort to prove his theory that modern man is actually less intelligent than his primitive ancestors, a mad scientist concocts a serum that transforms him into "The Neanderthal Man." But instead of getting smarter, he, of course, becomes a savage beast who will stop at nothing to claim the woman he wants. Robert Shayne, Joyce Terry, and Richard Crane star. 159 min. total. Widescreen; Soundtrack: English. Two-disc set.