One of a spate of giant animal films produced by Hollywood during the Fifties, “Tarantula” is superior to most of them in two major respects. The first is the acting of Leo G. Carroll, as Professor Deemer, the mad scientist whose good intentions go tragically awry. (Who would have thought that randomly irradiating animals would be a bad idea?)
The second is the quality of its visual effects: the film used real animals shot against reasonably convincing mattes as much as possible. Compared to the giant ants of “Them!”, shot a year earlier, it was a quantum leap in effects quality. Jack Arnold, who directed this film, would use the same technique to even greater impact in “The Incredible Shrinking Man” two years later (although in that case, it would deal with shrinking rather than growing).
Science Fiction Double Feature — Rocky Horror Picture Show original cast