Pod People (Invasion of the Body Snatchers)

Pod people (also known as The Body Snatchers) is a nickname given to an alien species featured in the 1955 novel The Body Snatchers by Jack Finney, the 1956 film Invasion of the Body Snatchers, the 1978 remake of the same name and the 1993 film Body Snatchers. Not to be confused with the 2007 film Invasion of the Pod People though they share similar themes.

The Pod People are a race of nomadic, extraterrestrial parasites originating from a now dying planet. Realizing that it was only a matter of time before the planet's resources would be completely depleted, the pods somehow evolved the ability to defy gravity and leave their planet's atmosphere in the search of a new world to colonize. For millennia, the pods floated in space like spores, propelled by the solar winds, some occasionally landing on inhabited planets. Once there, they would replace the dominant species by spawning emotionless replicas; the original bodies would then disintegrate into dust once the duplication process was completed. They would then consume all of the planet's resources, only to then leave in search of yet another new world. Such a consumption was apparently the fate of the civilizations that once inhabited Mars and the Moon. The Pods' sole purpose in life was that of individual survival, with no attention given to the civilizations they conquered or the resources they squandered. The duplicates had lifespans of only five years, and could not sexually reproduce. Their invasion of Earth was short-lived: unable to tolerate the sheer determination humanity displayed in defense, the Pods abandoned the planet, leaving behind a small population of duplicates, who died shortly after.

One of the pod people hints at their extraterrestrial origin and purpose without fully explaining it. In the end Dr. Miles Bennell, played by Kevin McCarthy, gets away from the town and tells his story to a psychiatrist. A truck carrying pods is involved in an accident; thereafter the psychiatrist believes the story. He then asks the FBI and police to quarantine the town. The audience is left to only wonder whether they were successful or not. The original ending was less hopeful about the fate of humanity, ending before McCarthy escapes to a psychiatrist. The final shot is of him standing in the middle of a highway shouting warnings at passing cars and then directly at the camera.

...
Wikipedia