Xenomorphs are a fictional extraterrestrial species that play the antagonists in the "Alien" film series. The term "Xenomorph" is derived from the Greek words "xeno," which means "stranger" or "alien," and "morphe," which means "form" or "shape."
The life of a Xenomorph consists of four phases. At phase one, it is an egg with a soft covering. At the second phase, it hatches from the egg as a Facehugger, which is a spider-like creature with a tail. The Facehugger implants an embryo into the throat of the being it latched onto. The embryo develops inside the host's body. In the third phase, the fully developed embryo, called the Chestburster, eats its way out of the host's body and immediately looks to feed. Once it has done so, it sheds its skin and fully grows into a Xenomorph, the fourth and final phase.
The appearance of the Xenomorph depends on its host. The human phenotype is around 7 to 8 feet with a long, muscular tail and a large, curved, oblong head.
The Xenomorphs lack a technological civilization and are only interested in spreading their species and multiplying their numbers. They are eusocial like bees and wasps, with a single fertile queen laying all the eggs.
The Xenomorph was designed by the Swiss surrealist and artist H. R. Giger.