Posted Apr-05-2018 11:46 AM
The Alien Movies, Comic Books, Toys, and Games have painted a picture on what a xenomorph should look like.
I'm going to go on an in-depth analysis on what is a xenomorph.
First lets get what is a true xenomorph out the way. The name xenomorph, even if it was a wastebasket name, was given to the titular creature by Lt. Gorman and since has been the creature's name throughout the Expanded Universe. This name was given to the creatures on LV-426, there for all xenomorphs who originated on LV-426 are true xenomorphs.
From Big Chap/Drone to Bug Stomper/Warrior and the First Acheron Queen to Dragon/Runner (Dog/Ox Alien) are what I like to call "baseline Xenomorphs".
If we think of the xenomorphs under a single genus and species, baseline xenomorphs would be the sole surviving member of its species as of 2179, the time of its unofficial naming. Any deviations outside of the xenomorph species natural hybridization ability can be consider as different species or subspecies, depending on the greater physiological changes from the core xenomorph physiology.
Offshoot 1: The Red Army Xenomorphs from the comics are depicted as a natural mutation, physically they resemble a baseline xenomorph from the Alien trilogy, except they have red exoskeletons rather than black exoskeletons.
Offshoot 2: The Clone Xenomorphs from Alien Resurrection are depicted as an unnatural hybrid of human and xenomorph genome, due to cloning of Ellen Ripley's blood sample. The Clones are physically different from their baseline ancestors, their heads are more cigar shaped, they have a more pronounced chin, they have a bladed thagomizer accompanied by elongated tail spikes, rather than a stinger accompained by smaller and uniformed length tail spikes.
Offshoot 3: The Protomorphs/Planet 4 Xenomorphs from Alien Covenant are if we go with David's origin of the species, the direct ancestor of the baseline Xenomorph species. If we go with the Engineer origin of the species, then the Planet 4 Xenomorph would just be an unnatural decedent of the baseline xenomorph, much like the clone xenomorphs.
Offshoot 4: The AVP xenomorphs resemble heavily like the Clone Xenomorphs. I keep getting commentors on all the Alien lore videos i comment on: claiming these xenomorphs achieved convergent evolution to merely look like the clone xenos. I on the other hand have two hypothesis on this matter: If we go with David's origins, then these creatures are not only excluded from being a xenomorph species but are ejected from being part of the same genus and therefore cannot not be labeled as xenomorphs.
However this would still mean they are a type of Xenomorphid, just not true Xenomorphs because the Predators would of had to gain access to the black goo and created their own xenomorphoid and thus were not the same creatures encountered on Lv-426.
However again, if we go with the baseline xenomorphs were of Engineer origin than the AVP Xenomorphs would be just as much of a xenomorph as lets say as the Clone and David's variants.