The Strange World of Planet X (1958) is a British science fiction horror film, and a cautionary tale about science. It was also known as Cosmic Monsters, The Crawling Terror, The Cosmic Monster, and The Crawling Horror.
The film was adapted by Paul Ryder from the 1957 Rene Ray novel of the same name; a TV serial adapted by Ray aired in Britain in 1956.
A monomaniacal scientist, Dr. Laird (played by Alec Mango), has invented ultra-sensitive magnetic fields, which attracts objects from space. Strange things begin happening, including a freak storm, and insects and spiders mutate into giant monsters. An alien spaceship appears over London and mankind is warned against the dangers of this scientific experiment.
Forrest Tucker as Gil Graham
Gaby André as Michele Dupont
Martin Benson as Smith
Alec Mango as Dr. Laird
Wyndham Goldie as Brigadier Cartwright
Hugh Latimer as Jimmy Murray
Dandy Nichols as Mrs. Tucker
Richard Warner as Inspector Burns
Patricia Sinclair as Helen Forsyth
Geoffrey Chater as Gerard Wilson
Hilda Fenemore as Mrs. Hale
The plot of this low-budget film appears to have been inspired by The Day the Earth Stood Still (1951). On its original release it was not notably successful, but subsequently became something of a cult favorite due to television reruns.
Unusually, a theremin is used in the musical soundtrack.
The film supposedly inspired the B movie, Invasion from Inner Earth (1974).