Here's a bit about my own Xenomorph canon.
Yes, my canon, because, as everyone seems to have their own canon about them, so have I. You can't rely on the official canon anyways, because it contradicts itself wherever possible.
I've looked through everything and finally came up with my own concept that's a mix of canon info and my own universe.
Also, I know that the term 'Xenomorph' is not the species' name but a fancy way to say 'alien' as it's classic Greek for 'alien form'. I'm using the term as the species' name nevertheless, because it's impossible to either write or speak their real name. They have a very complex language of hisses, screeches and clicks which is impossible to pronounce by humans.
My Xenomorphs are a species that evolved naturally on a faraway and long forgotten world. They were aquatic beings that lived in symbiosis with other species on that planet. Their life cycle had already been the same as it's known in modern tales, but the hosts of their young didn't die but birthed the embryos naturally. The Xenomorphs were the top predators on their world and already had evolved to be almost invincible. They already had their jet black skin for camouflage reasons. Also, they already had their chitinous exoskeleton, their long spiked tails, their double jaws and long claws.
Unfortunately, a space faring race - that's known as the 'Engineers' to us - once landed on said planet and came across the Xenomorphs, immediately noticing their potential as a weapon, would they be able to tame and utilize them. Using their advanced technology, they were able to take a whole hive - a queen and an unknown number of her offspring - captive to take them to their home world for further research. The 'Engineers' scientists were top geneticists and as such were able to alter the Xenomorphs' DNA in a way to create the apex predator, aggressive and merciless. They intended to use the species as some kind of biological weapon against their enemies, knowing that a single specimen would be able to set up a whole hive and wreak havoc wherever they went. The fact that the Xenomorphs need living hosts to procreate came in handy as an extra way to thin out their enemies' numbers.
The 'Engineers', of course, did not only play around with the Xenomorphs' DNA but also seeded or at least influenced life on countless planets just to watch it grow and then destroy it. One of those many planets was Earth. It is said but not completely proven yet that they had their hand in human evolution as well.
One day however, for reasons unknown, the 'Engineers' decided to end all human life, because they didn't like what humans had become. They sent a spaceship in the direction of Earth. Its massive cargo were not only a huge number of Xenomorph eggs but also a substance that could alter the DNA of every creature that got in contact with it, changing them into Xenomorphs as well.
The 'Engineers' didn't count in the power of their own creation, though. Some members of the ship's crew were imprudent enough to get too close to some eggs, arrogantly thinking nothing would happen to them. Unfortunately for them, the eggs hatched. The rest of that crew's fate can easily be imagined... Lacking a necessary number of crewmen, the spaceship finally crashed on a faraway moon where the 'Engineers' fought a more or less successful fight against the Xenomorphs that had taken over their ship. In the end, though, both 'Engineers' and Xenomorphs were killed by each others' hands.
The eggs that hadn't hatched yet, lay dormant in the ship's cargo bay for about 2,000 years.
It was then, that another space faring race, the Yseti (this is their commander: ananya-talvi.deviantart.com/ar…), passed the before mentioned moon by accident and received the distress call the 'Engineers' had sent out in a last attempt of survival. Of course, the Yseti decided to find out who sent the distress call and sent a landing party to the moon. Those scientists and soldiers found the derelict spaceship and, with great care, checked its condition and cargo. They didn't find anyone alive, naturally, but they checked the logs and recordings the 'Engineers' had left and, therefore, they were informed about the cargo's nature. The scientists among the landing party insisted on taking the Xenomorph eggs to Yseti Prime for further examination. Commander Tali agreed, so they brought seven eggs aboard the Yseti spaceship. Those seven eggs were the only ones that were still 'alive' while all the others on the ship had died in those 2,000 years of dormancy.
As soon as they arrived at Yseti prime, the scientists studied not only the eggs but also every single recording they had found on the 'Engineers' spaceship, thus perfectly knowing what those eggs contained and what they had to expect, would they decide to actually study an adult Xenomorph. After some discussion, one of the scientists agreed to become host to one of the Xenomorph embryos. He was sedated, then the other scientists brought one of the eggs and allowed it to hatch. As usual in the process, the facehugger attached itself to the sedated scientist's head and placed an embryo inside his body.
Three days later, the embryo had grown enough to leave the host's body, so the scientists carefully removed it in a complicated surgery. Both host and larva survived undamaged (except the host's surgery wounds, of course, but thanks to the Yseti's advanced medical technology, there was nothing to worry about - he was completely fine after three days). Knowing about the Xenomorphs' living conditions from the 'Engineers' records, they put the little Xenomorph in a big, dark and warm room to give it the peace and time it needed to grow. They also provided it with food.
It took only six further days for the Xenomorph to reach adulthood. It had become a strong and beautiful male. The Yseti treated him like an equal from the very first moment and gave him the respect he deserved. Due to this, the young male began to trust the scientists and started talking to them telepathically - a means of communication both the Yseti and the Xenomorphs are capable of. He also told them his name, Sanjay, because every Xenomorph is born knowing their name, given to them by their mother in the moment she lays the respective egg. With Sanjay's consent, the Yseti decided to also let the remaining six eggs hatch. Finding hosts wasn't difficult at all, because the Yseti are very curious and open-minded. Also, they had nothing to fear as long as they were in the care of a good surgeon the moment the embryos were about to get born.
In the course of about two weeks five further males (Samudra, Samanyu, Ajani, Ajay and Vijay) and a female (Jaya, who's called 'Shadow' by everyone because of her extremely dark skin) were born. They were integrated into the Yseti society as equals without a question. The Yseti don't know such stupid things as racism.
The Yseti respected the Xenomorphs' sentience and intelligence from the very first day, that's why those Xenomorphs never acted hostile. I suppose, if humans had taken the same approach in the few encounters they had with Xenomorphs, it would have turned out just like that. Xenomorphs are not hostile by nature, but when they feel threatened they, of course, defend themselves.
Sanjay and his siblings told the Yseti about their hive memory that holds a lot of information about their species, its history and origins. The Yseti knew of the 'Engineers' and had already wondered where they had gone so suddenly. The Xenomorphs had fought so violently against the 'Engineers' on the before mentioned spaceship in an attempt to free themselves from slavery. They were more than lucky that it was the Yseti who had found the last living eggs, because now their species can live in freedom.
Unfortunately, the Xenomorphs on Yseti Prime didn't know the coordinates of their original home world, that's why they asked the Yseti to help them find it. Like every Xenomorph, the most important thing for them was to find their mother, the queen of their original hive. Knowing nothing about her whereabouts saddened them so much that the Yseti decided to find her, no matter the cost. The most important thing for the Yseti, after all, is to help others in need.
Commander Tali took it on himself to find the queen. Of course, he didn't know where to look for the Xenomorphs' original home world, but he knew where the 'Engineers' had lived, so he steered his spaceship to their planet. There he found only destruction, evidence for a war that had been fought with all kinds of horrible weapons. It took Tali and his crew a longer while to put all the pieces of information together that they found on various places, but when they understood the whole story, they were fascinated.
On the 'Engineers'' home world - just like on the before mentioned spaceship - the Xenomorphs had risen to free themselves from slavery. The 'Engineers' had made the mistake to overlook the fact that their creation had developed intelligence higher than their own, and that their survival instinct exceeded everything else. So in the end, despite the 'Engineers' advanced weaponry, they were completely destroyed by the Xenomorphs, but unfortunately the death toll on the Xenomorphs' side was enormous as well.
Commander Tali and his crew took a long time to seek the planet for life signs of any kind, hoping that the queen mother of the Xenomorphs back on Yseti Prime was still alive somewhere. At a time when they were almost about to give up, they finally found the last existing hive. Being lucky to communicate telepathically with those Xenomorphs, they could make clear that they were coming as friends, so the queen, Nayamandra, let them enter her chamber. She listened to their story carefully, but after all she had to witness with the 'Engineers', she had a hard time believing the Yseti were speaking the truth. So Commander Tali allowed her to read his mind fully without his mental shields up. That's when she believed him, and she was also excited about the fact that seven of her children were living freely among the Yseti. She asked the Commander to take her and her few remaining children to Yseti Prime to what he happily agreed. He understood that she couldn't live on the 'Engineers' home world any longer. Nayamandra turned out to really be the mother of Sanjay and his siblings.
Now, more than thirty years after those events, there's a healthy hive living on Yseti Prime. Thanks to the willingness of many Yseti to become hosts of her young, Queen Nayamandra's hive consists of more than 300 Xenomorphs, added to the seven who were born before her arrival on Yseti Prime and the twelve she had brought with her. She had laid those 300 eggs back on the 'Engineers' home world and had brought them with her on Commander Tali's spaceship as well. Apparently, she and her hive are the last of the Xenomorph species, but she still has hope that there are others living on other planets who had been brought there by the 'Engineers'.
Her hope is legit, indeed, because not long ago there was found a small hive in Antarctica. But as those Xenomorphs had been bred by a rogue Yautja clan for the sole use in their cruel hunting game, only one of them had survived the massacre. The queen, unfortunately, had been killed alongside with her young. Nayamandra happily took the sole survivor in and nursed him back to health - and fell in love with him.
Due to the fact that he's from another hive and, therefore, not her son, she chose him as her partner. It's great luck for the hive to have a fertile male and female now, because now Nayamandra is able to lay new eggs and have further children.
As the Queen is the only fertile female in the hive and only needs one male that's chosen by her, my Xenomorphs are all asexual with male and female mind patterns. The queen lays a great amount of eggs in her laying cycle once a year which normally lasts about a month or two. She's only fertile in the few days before she starts laying.
My Xenomorphs all have jet black skin with only a few hints of colour, mostly on their head carapace. Therefore, it's hard to distinguish them when not used to them. They're very playful and friendly.
They're all connected through the hive mind, thus knowing everyone's whereabouts at every time. They'd fight and even die for their queen without question, but they'd do it because of love not because she'd force them. My Xenomorphs normally communicate telepathically with each other, but they also speak their own language which can't be understood by humans (we'd only hear hisses, screeches and clicks that don't make any sense to us).
Also, there are no different 'classes' in Nayamandra's hive, such as drones and warriors. They're kinda all warriors.
Males and females can be easily distinguished. All males have ridged head carapaces while those of females are smooth.
Knowing that they're very likely the last of their kind, the Yseti are protecting them from every possible attacker.