The main stage of the Xenomorph life cycle, at this point they are identified as "Xenomorphs" (Changing Form). There are 4 main distinguishable castes of Xenomorphs, with some small variants.
"I admire its purity. A survivor... Unclouded by conscience, remorse, or delusions of morality."
The lowest of the caste, the Drones are young Warriors. They tend to the hive, creating the resin walls and moving the queen's eggs. Because they are just young warriors, new hives will be almost completely drones, and old ones will be mostly warriors. Drones are easily identifiable by their reflective dome heads. The dome head will later be shed as it grows, revealing what is underneath.
"We'd better get back, 'cause it'll be dark soon, and they mostly come at night... mostly."
Usually thought of the truly adult Xenomorph, the warrior is the brute force of the Queen. If a potentially dangerous species enters the hive a huge mass of warriors (average hives having about 100-200 expendable warriors) will surge forward and rush the offenders, swarming them. While one warrior is deadly in its own right, swarm tactics are preferred by the queen. Older warriors will become "Carved" which just means it has a more ornate crest as well as being about a foot larger and longer.
"There was one big ************, like twice the size of the others... That thing could really scream. I never heard anything like it."
Most easily identifiable by their size and crest, Praetorians are the last line of defense for the queen. They are rare, and the way they are born are unknown. It is theorized that they are what happens when a queen is born into a hive already with a queen, a second embryo that is implanted with the queen embryo that develops to protect her, or just a regular Xenomorph that has molted in large hives. Their massive size (over 10ft tall) make them an extremely honorable trophy for the Yautja.
"She's badass, man, I mean BIG!"
The queen is the driving force of the hive. All xenomorphs live and die for their queen unquestionably. By far the most intelligent of her species, a queen is the only one to show emotion, seeking vengeance and showing spiteful hatred when an egg is destroyed. In rare cases, a Queen will mourn for her lost eggs, letting out a deafening wail. A queens most noticeable features are its size (30-40ft), massive headcrest, clear teeth, and blue accents on it's exoskeleton. As I've suggested, the queen usually is immobile with a massive egg sac attached over its tail and needs its children to defend it from intruders. In a case of emergency, the queen can break free from its egg sac and deal with problems itself, but this process is extremely painful and thus she is reluctant to do so.
Next will be special species (Behemoths, Runners, Boilers, etc) then it'll be all wrapped up!