The species made its debut in the 1979 film Alien, and reappeared in its sequels Aliens, Alien 3, Alien: Resurrection, as well as two crossovers Alien vs. Predator and Aliens vs. Predator: Requiem, and finally in the prequel of the series, Prometheus. It also appears in various literature and video game spin-offs from the series.
Unlike many other recurring enemy extraterrestrial races in science fiction, the Xenomorph's are not an intelligent civilization, but predatory creatures with no higher goals than the propagation of their species and the destruction of life that could pose a threat. Like wasps or termites, Xenomorph's are eusocial, with a single fertile queen breeding a caste of warriors. The Xenomorph's biological life cycle involves traumatic implantation of parasitic larvae inside living hosts, which mature before erupting from the host's chest. Their design deliberately evokes many sexual images, both male and female, to illustrate their blurring of human sexual dichotomy.
- The Xenomroph appears in Return of the Xenomorphs Part 1: Rise of the Flood.