This amazing sci-fi film, released in 1955 and directed by Jack Arnold, stars Leo G. Carroll, John Agar and Mara Corday. Although the movie was set in Arizona, Tarantula was shot in California, with desert scenes filmed in Apple Valley. This movie has it all – suspense and a towering 100 feet of pure, furry tarantula terror.
The movie starts as a man in pajamas with a disfigured face stumbles through the Arizona desert, then falls and dies. Matt Hastings (John Agar), a doctor from a nearby town, is called to look at the body. When he arrives, he is surprised to learn that the dead man in the desert was someone he knew, a research scientist named Eric Jacobs (Eddie Parker). Dr. Hastings asks to perform an autopsy to attempt to find out the cause of death. The sheriff refuses, ruling an autopsy unnecessary as Jacobs' associate, Dr. Gerald Deemer (Leo G. Carroll), had signed the death certificate and there appeared to be no indication of foul play.
Dr. Hastings is determined to find what killed Jacobs, so he drives 20 miles out of town to visit the dead man’s colleague Deemer at his lab. Hastings learns that Deemer and Jacobs had been conducting experiments on animals in an effort to use an atomic isotope to create a super nutrient.
Hastings learns that the experiments proved to be such a huge success that some animals were able to thrive and grow on the nutrient without any food, although the nutrient had not been perfected. Hastings also learns some of the animals had died after receiving the injections, and still others kept growing – to massive proportions. The latter include a white mouse, a guinea pig and a Mexican tarantula.
Deemer discloses to Hastings that the cause of Jacobs' death was the result of Jacobs injecting himself with the nutrient, which killed him in four days. What Deemer does not tell Hastings is that Jacob also injected his research assistant, Paul Lund (Eddie Parker), with the same nutrient.
After Hastings leaves, the deformed Lund shows up to attack Deemer and destroys the lab. Throughout this rampage, the lab catches fire and the glass front of the tarantula's enclosure is shattered by the heat.
Next, the tarantula escapes outdoors, unnoticed. Lund collapses and dies, and Deemer buries Lund's body and conceals all traces of the grave.
The next day, a new lab assistant arrives in town, the attractive Stephanie Clayton (Mara Corday). She goes by "Steve," and agrees to assist in the lab as part of her master's degree program. After being told she would have to wait a few hours for a cab to drive her to the lab, she runs into Hastings, who offers her a ride.
When Hastings and “Steve” arrive at the lab, they notice the damage. Deemer tells them the fire was caused by an equipment malfunction. He indicates that all the lab animals were killed in the fire, and avoids answering questions about what happened to his previous research assistant.
Steve begins working in the lab, and begins to notice disturbing changes in Deemer's appearance and demeanor. Meanwhile, the now average super-sized tarantula ravages the countryside as Hastings tries to unravel a mystery that includes cattle carcasses picked clean and pools of arachnid venom up to eight feet in diameter.
Once he puts two and two together, Hastings begs the Sheriff to gather law-enforcement personal and explosives so they can try to destroy the creature that is killing livestock and humans.
The tarantula eventually returns to the lab, and then pursues its human quarry down the road toward the town. After several failed attempts, the spider is eventually destroyed by a napalm attack launched from a jet-fighter squadron.