The Xenomorph is a fictional extraterrestrial creature that was first introduced in the 1979 science fiction horror film "Alien," directed by Ridley Scott. The Xenomorph, also known as the Alien, is the primary antagonist of the "Alien" film series, which includes several sequels, prequels, and spin-offs.

The Xenomorph is a highly aggressive and deadly creature with a distinct life cycle. It starts as an egg-like organism called a Facehugger, which attaches itself to a host organism's face and implants an embryo inside. The embryo later develops into a creature known as a Chestburster, which bursts out of the host's chest, killing it in the process. The Chestburster then grows rapidly into a fully-grown Xenomorph, which is a sleek, biomechanical creature with a long, toothed head, a segmented exoskeleton, and a long, whip-like tail.

The Xenomorph is known for its incredible strength, agility, and resilience. It possesses a protective exoskeleton, acidic blood, a second set of jaws within its mouth, and a barbed, extendable inner mouth that it uses to attack its prey. The creature is highly adaptable and capable of surviving in various environments, making it a formidable and dangerous predator.

The Xenomorph has become an iconic and influential creature in popular culture, and it has appeared in numerous films, video games, comics, and other media beyond the original "Alien" franchise.