stop-motion animation that had previously worked with King Kong animator, Willis O'Brien. His work also appeared in such films as 20 Million Miles to Earth, and 1953's hit film, The Beast from 20,000 Fathoms. That film, based on a short story by Ray Bradbury, featured the fictional Rhedosaurus, which is thawed out of the Arctic by atomic testing and begins to ravage sections of the United States. Its massive success set off a new wave of science-fiction monster films. Like the 1930s, these movies demonstrated a mix of horror and science fiction, now often mixed with anxiety of nuclear technology or the dangers of outer space. Them!, It Came from Beneath the Sea, and Tarantula, released within two years of The Beast from 20,000 Fathoms, all featured over-sized animals created by nuclear testing. It! The Terror from Beyond Space, The Blob, The Angry Red Planet, and Kronos, on the other hand, featured alien monsters. Still others, like The Fly, The Amazing Colossal Man, and The Incredible Shrinking Man, focused on human mutation. This trend was not limited to the United States; perhaps the most successful monster movies were the kaiju films released by Japanese film studio Toho. The 1954 film Godzilla, with the title monster attacking Tokyo, gained immense popularity, spawned multiple sequels, led to other kaiju films like Rodan, and created one of the most recognizable monsters in cinema history. Japanese science fiction films, particularly the tokusatsu and kaiju genres, were known for their extensive use of special effects, and gained worldwide popularity in the 1950s. Kaiju and tokusatsu films, notably Warning from Space (1956), sparked Stanley Kubrick's interest in science fiction films and influenced 2001: A Space Odyssey (1968). According to his biographer John Baxter, despite their "clumsy model sequences, the films were often well-photographed in colour ... and their dismal dialogue was delivered in well-designed and well-lit sets." The financial success of these films relied on studios drawing in large teenage audiences, taking advantage of popular techniques such as drive-in theaters and 3D, notably used by movies such as Creature from the Black Lagoon or Gog. In addition to increasing the audience size, many science fiction films of the time were created with minuscule budgets; the phrase "B-movie" came to signify a formulaic genre film made with low production costs (usually for less than $400,000). This concept was exemplified in a studio memo about the movie Them!