A great big series theory about the alien and predator universe

The Grand AVP theory

There are several things that will be said in this theory that many will not like first of all, Xenomorph XX121 is not a Xenomorph, can't be. It is likely David's final Xenomorph design but it's too different from those in Alien 2, Resurrection, AVP and AVPR.

When a queen is not present in a certain vicinity or the current queen's life is in danger, a special carrier facehugger commonly mistaken for the queen face hugger can be produced to carry an egg away to a safe area or vehicle to spread to a new world. In Aliens, the face hugger would have been produced to take an egg onto the sulaco which the queen understands can travel off-world because of the shared Xeno hive mind which could see the ship flying. The face hugger itself is black for camouflage, larger than regular facehuggers with an especially broad back for the egg to rest on, long webbed legs for swimming or gliding and a sharp tail for protection. Since it's small, it would have had an easy time sneaking on board with or without Bishop's help depending on his orders from Weyland Yutani who most likely commanded him to do it. The facehugger can then stow away somewhere until Newt, Ripley and the other one are in cryo pods before coming out and burning the egg on the wall with its acid spit where it would survive the take-off. Once in space, the face hugger can crawl out of the egg, a regular one as we saw in the intro to Alien 3, got into Newt's cryopod, implanted the queen into her and the carrier was about to impregnate Ripley most likely and caused a fire during the process which resulted in the cryo-pod ejection. This would be a few hours after the impregnation of the queen which means it would be almost fully developed until the pods crash into the ocean on the prison world and Newt starts drowning. The  partially developed queen then leaves Newt through the throat and swims into Ripley where it has to break down its current genetic structure sensing new DNA in its host, this is to better adapt it to its environment so it takes a while to break down and rebegin the gestation period again. The carrier facehugger was already inside of Ripley's cryo-pod when it ejected so it came to the planet with her and swam onto shore where the ox herd was and with its broad back, it was able to account for the animals shaped head and successfully impregnate it. Therefore Xenomorph XX121 can't be a Xenomorph or else it would have been a queen. The only other example we see of this is the Protomorph in Alien Covenant which looks more like Xenomorph XX121 than Xenomorph XX121 does to the other Xenomorph in the other films. There are some obvious differences between XX121 and the Protomorph it is just a prototype and the finished product is what the crew of the Nostromo discovers in Alien. David's complete work. It's entirely possible for there to have been more than one derelict spaceship on LV426 since it was the engineer homeworld before they were wiped out.

Now we can assume that the Predators and the engineers are at war since the Predators are built on it and would be looking for a battle. The Predators are clearly older than humans since they are way more advanced and excluding the physics element on time-space and gravity and how it affects time, the predators could have been at war with the engineers for thousands of years prior to the first humans even evolving. We can see that the engineers like bioweapons and the predators love to hunt so its possible that the engineers created the black goo as a weapon against the predators before after realizing it's potential through researching it, that it can create and mutate life forms. Sensing an opportunity to advance their progress in the war, an engineer sacrificed themselves on Earth using the goo to trigger an evolutionary chain reaction hoping that whatever sentient life was created would help them in the war against the predators. However, the engineers also create a type of xenomorph/protomorph with the goo and the data banks are hacked by the predators who after discovering the opportunity steal the research and produce the xenomorphs to aid their hunt in AVP and use them against the engineers. Realising how the xenomorphs can be enhanced further, the predators begin to conduct their own research into xenomorphs and create the xenomorphs seen in AVP, AVPR, Aliens and Alien 3. Instead of showing up at Lv426 (engineer homeworld) in the open, they capture and engineer ship while at war and infiltrate them successfully which is why there was a ship containing predator xenomorphs and David's xenomorphs. The predators would have kept some of the eggs for themselves and left the rest on the ship which was abandoned on LV426 and would hopefully trigger and infestation wiping out the engineers at the source. This didn't happen however and the war raged on between the two races and over time, the engineers discovered LV223 and used it to research the black goo before an outbreak killed them. It's also likely then, that when David accessed the engineer's ships controllers, he found a way to download the data bank into his memory without realizing it. Included in that data bank was the xenomorphs which he then believes he thought of himself when he didn't. He's just mimicking what the predators and engineers had done thousands of years earlier but couldn't or even didn't want to realize that he didn't think of it himself.

During the war, however, the predators find out about the humans on Earth under engineer protection because they believed that humans would help the engineers win the war against the predators. In retaliation to this, the predators went to Antarctica where the primitive humans believed they were Gods and were enslaved by the predators and build grand pyramids and sacrificial chambers that would truly test the young predators. Using the final design of xenomorph, the Predators held a test every century to test the predators and to remind the engineers who were boss. Until of course the predators become overwhelmed by the amount of xenomorphs and kill them all including the ancient people who lived there and sacrificed themselves as an honour. At the end of AVP, the queen falls into the ocean and freezes which are perfect because this follows into the AVP 2010 game. Its continuously demonstrated that xenomorphs don't breathe or require oxygen to live so the queen would just be frozen down there for 100-200 years when Weyland Yutani goes back to the pyramids and discovers the frozen queen in the ice. All they have to go off is Alexa's report from 200 years previously so, at some point, a facehugger escapes and impregnates a predator bringing the predators from AVP 2010 to the planet where the queen had been transported after thawing out. After limited research, Weyland decided that they would make excellent bioweapons and for another 200 years, have the same opinion. Thus began the training programme and the whole specimen 6 Malachi. In the case of AVPR the predalien produced had to have been a partially developed queen since it could impregnate humans with the belly bursters (The director of the film even stated that this was the case) and since the queen was frozen in Antarctica, the predalien would begin developing into a new queen since it was it's nature as the oldest of the new hive of xeno's it controlled. However, it was killed before it could finish evolving. To back this up, I have the fact that the predalien in the 2010 game didn't impregnate anybody or not that we saw anyway so if it was just a natural trait, it would have done it when it didn't so the predalien from AVPR must ave been a partially developed queen. What's important to note is that specimen 6 survives and becomes a queen after arriving on what is most likely Earth since the ship would be on an autopilot to Earth. At the end of Alien Ressurection special edition, we see that the Earth is void of all human life so what most likely happened is that specimen 6 started a hive and destroyed the human population on Earth. However, humans still survived on other planets and the aliens on Earth most likely ran out of food or hosts to reproduce with and died off which is why Weyland Yutani needed Ripleys alien queen so much in Alien Ressurection and couldn't take a specimen from Earth. Perhaps they were trying to train a group to combat those on Earth and reclaim the planet. Or perhaps they went to fight the Yautja with their own creations. At the end of the day this is just a theory if any mistakes or errors are spotted please let me know so I can refine it.