A normal adult Vaess has a humanoid torso with two arms ending in six-fingered hands. They have hair, though besides the hair on their heads there is very little, and two glossy eyes. Their mouths are full of needle-like teeth and their fingers have small, chitinous claws. Their wrists contain retractable poisonous spurs, each caste with their own type of venom.
Their lower bodies consist of a vaguely rounded-rectangular "hub" to which their four arachnid-like legs are attached; the back legs are longer than the front, and each leg ends in a clawed point. There is also a pair of small pedipalps at the front end of their lower hub between the legs; they produce a web substance. A pair of speciallized appendages near the back legs can take this web substance and infuse it with the Vaess's venom, shaping it into a sort of disc and throwing it as a projectile.
Vaess begin as eggs, eventually hatching into small, pale young, which look like smaller versions of adults. After about 4 years, with molting every 3 months, they grow into adolescents and begin developing caste characteristics. From there they become young adults at about 14 and full adults at 20.
The core castes are usually between 5-6 feet in height, with the Kahzess from 6.5-7.5 feet.
Melee weaponry includes tonfa-style forearm swords, katars, and push-daggers. Archers sometimes appear, though for projectile weaponry most Vaess just use their web discs.
Vohtess have dusty reddish armor on their lower section, and their skin has a reddish tint; their eyes are green. They are the most aggressive as well as the most heat-tolerant, and commonly take leadership roles. Their venom causes burning pain, making it hard for the affected creature to concentrate on anything.
Vohtess have been known to enter berserker-like states and charge, ignoring pain and running down foes.
Nogess have dull navy-colored armor on their lower section, and their skin is tinted grey-blue; their eyes are orange. They are relatively more calm than some other breeds, and act as balancing points and peacemakers for the various traits of the others. Their venom incites dehydration in the target, weakening it; it also can cause underwater targets to reflexively swim to the surface. Uniquely, they can emit a sonic wave with disorienting properties; enough of them using it simultaneously can cause huge resonance pulses to damage structures. They are the best swimmers, though they prefer to use their physics-defying ability to skate on the surface of water like vastly oversized water-striders.
Keless have greenish armor on their lower section, and their skin is tinted greenish; their eyes are pale red. They are the most capricious caste, with a tendency to dart in and out of combat, making use of alarming spinning maneuvers to swing their exceptionally sharp leg-claws in slashing arcs. Their venom is a powerful acidic compound, but most Vaess can neutralize it with a different fluid they can produce---this is a safety measure.
Sukess have greyish-white armor with hints of blue; their skins are pale bluish and their eyes are teal. They are the planners, directing when to attack or retreat; they are also the most resistent to cold. Their venom causes the movement of victims to be restricted; the more they try to move, the harder and more painful it is to do so.
Sukess are capable of entering a torpor-like state, making their life signs hard to track.
Rupess have dull brown armor with red hints; their skins are somewhat tan and their eyes are dark blue. They are the spies of the Vaess, using their limited ability to change their coloration to blend into their environment. They usually stalk foes until the opportunity shows itself, then attack. Their venom causes exhaustion, and they are the best at throwing web-discs.
Oohness have black armor and grey skin, with gleaming yellow eyes. They are the shyest and most submissive, often pushed around by the more aggressive Vohtess or Keless. However, they are deadly cunning and not to be underestimated. They prefer the dark, and have better vision in the shadows than any other caste. Oohness have limited telepathy and vocal mimicry, allowing them to, for example, read someone's mind and then lure them into a trap by mimicking one of their friends. Their venom causes numbness and lack of coordination.
Kahzess have purplish-grey armor and whitish skin, and their eyes are gold-colored. They are the elite caste and have a different body structure; their bodies are brawnier, their legs longer. Their front web-producing pedipalps are longer than normal and clawed, and their rear throwing 'palps are stronger as well. They also have a sixth pair of legs between the front and back ones, which are smaller but much more sharply clawed. Kahzess do not have a special venom; they only have the standard stunning venom that all Vaess have. Instead, they tend to use a dark form of sorcery allowing them to trap foes in a pocket shadow dimension shared by all Kahzess of the same Horde. This dimension suspends a target's vitals---they cannot starve, suffocate, or otherwise die---but is very hard to escape.
Kahzess are arrogant and brash. While the lower castes do not reproduce, Kahzess do.
A Vaess Horde generally works like this: they take over an abandoned establishment to use as the center of their hive, then spread out until they have covered enough ground to comfortably live in. The main reproduction of the species is very secretively done; if there is some sort of breeding queen, she is kept hidden even from most of her own hive.
The six core castes function as workers, guards, hunters, warriors, etc according to individual and caste skills. The elite Kahzess function as community leaders and elite guards for the central reproductive compound (the seeecret central reproductive compound!) as well as peripheral breeding couples. Since the six core castes are effectively sterile, there is little to no sex drive within them (but emotional bonding is still a thing).
Info on the main reproductive process of the hive (spoilers I guess).
The reproductive hub of a hive is the Monarchs, the Vaess King and Queen. A Vaess becomes the hive's Monarch through the influence of their patron goddess, the bizarre and enigmatic Queen Mother.
The Queen is about 8 feet tall in an average stance on the ground, but most of her time is spent half-asleep in a sort of web that holds her while she is attached to her egg sac, a translucent muscular structure for laying eggs, which are brought to nurseries by an inner circle of Kahzess. The queen's skin is silvery-grey, and her chitinous lower body is glossy black and silver. Her rear pedipalps are no longer very good at throwing venomdisks, though her venom (which induces hallucinations in the target, who starts thinking they're mutating) is quite potent. Like Kahzess, she has a sixth pair of legs, these ones ending in armored talons for catching projectiles. Queens are fomidable; not only are they strong and agile when not attached to their egg sacs, they are strong psions.
The King is about 8.5 feet tall, with dusky reddish skin and a red-and-silver coloration to his underbody. He spends most of his time half-asleep next to the Queen and in mental contact with her. His psionic abilities are not as strong as hers, but he has powerful spellcasting abilities and can manifest a powerful energy blast from the blades on his middle pair of underbody limbs. He's also a damn good shot with his venomdisks, which induce temporary loyalty in the target. The King is a formidable force in battle.
The King and Queen spend most of their time half-asleep in mental contact, the Queen laying an egg now and then. Reasons for them to wake are 1) they need to mate again to keep up egg production, 2) a grave matter has to be brought before them, or 3) it's time for them to kick some ass.