Tarantula on AllMovie

A man with a strangely misshapen face, dressed in bedclothes, wanders out of the desert just outside the town of Desert Rock and falls to the ground dead. The county sheriff (Nestor Paiva) tentatively identifies the body as that of Eric Jacobs, a colleague of Professor Deemer (Leo G. Carroll), a research scientist who lives a few miles outside of Desert Rock. But Jacobs' facial features and bodily extremities are distorted to a point where he's barely recognizable -- the sheriff calls in Dr. Matt Hastings (John Agar), the local physician, who makes a tentative diagnosis of acromegalia, a glandular disorder that affects the body's growth. He also tells the sheriff that it can't possibly be acromegalia, because symptoms as pronounced as these take years to develop, and the man was in perfect health just three months earlier. Deemer seems cooperative with the investigation, but is also oddly secretive in his manner. Back in his desert laboratory, the professor is going over tests of a chemical on various animals, all of which are jumbo-sized: Guinea pigs the size of rabbits, baby mice the size of full-grown rats, and a three-foot long tarantula. Suddenly, the professor is attacked by his assistant (Eddie Parker), whose face and hands are distorted in the same manner as Jacobs, and who injects the helpless scientist with his experimental chemical before collapsing dead. A fire starts during the attack and Deemer barely manages to escape, but the laboratory is destroyed, seemingly along with all of the test animals. Everything appears to return to normal, even as the professor gets a new assistant, Stephanie "Steve" Clayton (Mara Corday), who begins a romance with Hastings when she's not at work. Little do any of them realize the chilling sequence of events started in Deemer's lab, as his experimental chemical begins its work of destroying him internally, and the one surviving subject of his experiments prowls the desert, stalking and killing ever larger prey....