For a species that doesn’t have any form of interstellar travel, or even the capacity to fully comprehend what that even means, Xenomorphs sure seem to be on a lot of different worlds throughout the Alien franchise–and now, it is finally explained how that is possible: Predators.
When Xenomorphs were first introduced in the 1979 film, Alien, they were isolated to one world: LV-426 aka Acheron. In both Alien and the sequel film, Aliens, Xenomorphs were only ever shown on Acheron, and only ventured away from the planet when a Xenomorph or two hitched a ride on a human spaceship–but that only happened twice (Alien and Alien 3) and resulted in the nearly immediate deaths of those Xenomorphs. Even Xenomorph clones didn’t make it off the ship they were created on in Alien Resurrection. So, how were they so widespread across the universe? The comic book continuations show humans traveling to a number of far-off worlds, and more often than not, a Xenomorph hive has already been established there. While it was originally assumed that the Xenomorphs were spread from planet-to-planet by the Space Jockey that was shown in the first film, one comic gives a much more satisfying explanation.
Predators Spread Xenomorph Queens from World to World
In Aliens vs Predator: War by Randy Sradley and Mike Manley, a human named Machiko Noguchi has been recruited by the Yautja following the events of the original Aliens vs Predator comic series, during which time she succeeded in killing a number of Xenomorphs and thereby earned the Predator’s mark of honor. However, she quickly learned that killing Xenomorphs was only half of the Yautja’s responsibilities, as they also had to ensure that the Xenomorph species was plentiful across the cosmos. In the first issue of this series, Machiko is with her team of Predators on an alien planet, trying to abduct a Xenomorph Queen from her hive in order to move her to a different world to seed it with life–thus creating yet another hunting ground for the Predators to conduct their rite of passage: the Blooding Ritual.
Every Predator, in order to reach full maturity as an intergalactic hunter, must first succeed in completing the Blooding Ritual, which requires them to kill a Xenomorph and then mark themselves with the Xenomorphs acid blood–a permanent branding of the highest honor. Machiko participated in the Blooding Ritual without even realizing it, which is why she became a Predator herself–which only goes to show how seriously the Yautja take this rite of passage. Since hunting Xenomorphs is so important to Yautja culture, the Predators have to make sure they are prevalent across the universe–hence, why Xenomorphs keep popping up on random planets throughout the franchise.
While this method of seeding practically any planet they come across with Xenomorph life is good for the Predators, it is pretty bad for the rest of the universe. Xenomorphs have the ability to terraform any planet they invade perfectly, and that process usually kills every trace of that world’s indigenous life. But, that matters very little to the Predators as they see any given planet as nothing more than a hunting ground for their most important ritual–a ritual that requires them to spread Xenomorphs across the Alien universe.