Alien: Covenant - What Does The Ending Really Mean?

7. Who Created The Xenomorph? Is It Even The Finished Item?

On the surface, this film seems to suggest that David is responsible for evolving the Xenomorphs from the DNA available from his human host and the weaponised alien pathogen, but a reading that simple isn't really the whole story.

If he was responsible for creating the monster, how did the Engineers have a mural of the same beast in their temple in Prometheus? Were they already on the experimental track towards creating this "perfect" creature themselves without putting the final pieces of the puzzle together that they needed the right hosts?

It's curious to see David appropriate the creature's creation for himself, but there's also a suggestion that this isn't actually the same creature we see in Alien and its sequels. Sure, it initially looks like the same beast, but the design is slightly different: it looks taller, sleeker and actually more refined (if slightly less terrifying), so it may be that David's Xenomorphs are entirely different to the Engineers' iterations.

That would also explain how he's able to "tame" his aliens, how he avoids being immediately killed by them (they have no issue killing Bishop despite him not being biological) and why the new-born Xeno mimics him weirdly when it's born. It wouldn't be at all surprising to reveal that this wasn't the real birth-point of the famous aliens at all.