The Alien, or officially known as Xenomorph XX121, is the primary antagonistic species of the Alien film franchise. The Alien is a recurring major threat, and while its exact characteristics and appearance change between movies, it remains one of the most dangerous creatures in the known universe. Aliens are also known for their constant association with the Yautja species (better known as Predators). The latter views the Aliens as the "ultimate prey"; those few hunters who survive encounters with the Xenomorphs receive great praise from fellow Predators.