Prometheus made several changes to long-established Alien features including introducing a new kind of facehugger to the franchise. However, while the horrifying monster was one of the most effective parts of the movie, Prometheus‘ trilobite also highlighted an ongoing issue that the Alien series still hasn’t managed to solve. Alien‘s titular antagonist is one of the most iconic creations in all science fiction. However, as Prometheus inadvertently demonstrated with its new creatures, the xenomorph (and its other associated lifecycle stages) present the franchise with a problem that’s almost impossible to overcome.