Alien (creature in Alien Franchise) - Life Cycle

Life Cycle

Aliens are eusocial life-forms with a caste system ruled over by a queen. Their life cycle comprises several distinct stages: they begin their lives as an egg, which hatches a parasitoid larval form known as a facehugger, which then attaches itself to a living host by, as its name suggests, latching onto its face. In the Alien 3 novelization, Ripley commented that this parasitoid would likely be able to use a host as small as a cat, or as large as an elephant.

The facehugger then "impregnates" the host with an embryo known as a "chestburster", which, after a period of gestation, erupts violently from the host's chest resulting in the death of the host.

The chestburster then matures to an adult phase, shedding its skin and replacing its cells with polarized silicon. Due to Horizontal gene transfer during the gestation period, the Alien also takes on some of the basic physical attributes of the host from which it was born, allowing the individual alien to adapt to the host's environment.

The adult phase of the Alien is known by various different names. The adult Aliens have been referred to as "drones," "warriors," "workers," and sometimes "soldiers," similar to the way ants have been defined. The names of the adult phase have also been used to name different types of adult phases of the Alien in numerous sources including video games, comic books, novels, and, of course, the films, but only in the commentaries by the team who created the films. No official name has been given to the adult stage of the Alien in the films themselves.