Tarantula, directed by Jack Arnold, features an enormous radioactive spider (the titular tarantula) that terrorises a small town. It was clearly inspired by Them!, which features enormous ants, though its special effects (back-projections of a real tarantula, and miniature sets) are a significant improvement. Like Godzilla, it has an anti-nuclear subtext.
Arnold directed a series of classic sci-fi films in the 1950s in addition to Tarantula, including Creature From The Black Lagoon and It Came From Outer Space. His pulp masterpiece The Incredible Shrinking Man also features a battle with an arachnid. Tarantula was spoofed nearly forty years after it was made, by Eight Legged Freaks.