Alien is a science fiction horror and action media franchise centered on the original film series which depicts warrant officer Ellen Ripley (Sigourney Weaver) and her battles with an extraterrestrial lifeform, commonly referred to as the Alien ("Xenomorph"), and the prequel series following the exploits of the David 8 android (Michael Fassbender) and the creators of the eponymous creatures referred to as the "Engineers".