I'll LOAN you the Khizht.
The Khizht are a semi-upright, Exoskeletal, 2m long by 1.25m tall race of omnivore gatherers. Biologically, they are carbon based, and use mostly the same amino acid and protein complexes as terran life. The have a 3 segment body, consisting of a head, a thorax, and an abdomen. There are two limbs associated with each body sement; the head has two sensory limbs (antennae), and two mouth-limbs (about 10cm overall), and the head has a complex mouth, plus two large compound eyes on the sides. There are two smaller eyes on the front of the face for identification of food; these are also used for reading. The head is comprised of about 8% of the overall body mass, and includes almost all sensory organs EXCEPT the brain; likewise, the forestomach is in the head The limbs on the thorax are two arms, and two interchangeable arm/legs.The Thorax consists of about 40% of the body mass, and contains the brain, and the gut. The abdomen has two legs, and two pedipalps modified for reproduction, and consists of about 35% of the bodymass. Excreatory and reproductive functions are localized in the abdomen. Lungs are decentralized; each body segment has 6 two-chambered lungs, each connected to two spiracles on the back. The inner ones are the intakes, the outter ones are outputs, and lung function is monodirectional.
The carapace, in order to support the weight is not terrifically thick, only 1-3 mm, but is backed by ribs of cartilage and keratin, which are fuesed to the carapace. Each lung and hart is a cartilaginous tube, to which the muscles attach. (These organs actually work on both intake and outflow strokes, with different muscle sets.)
There are many hearts; the primary ones are in the thorax, and are a pair of 1kg organs; a backup single one is in the abdomen.. A secondary heart works each the head, arm and leg, massing about 0.3kg each; the pedipalps, and head-limbs have atrophied to about 50-100 grams each. The blood is a multi-se fluid; it lacks the coagulatory functions, but is otherwise similar to mamallian blood in form and function. Most of the blood is formed bby organs in the abdomen. The circulatory system is compartmentalized, but there is exchange of fluids between compartments by specialized sphincters at each joint. The arterial system is highly developed, and is muscularized to aid in flow. The veinous system is less developed, and is semi-open to the body cavity of the thorax and abdomen. The digestive tract basically wallows in veinous blood, but is iteself also laced with arteries.
Limbs are composed of 3 long segments, each with a hinge joint, plus a hand of 4 digits, of two joints each. The "Hip" flexes fore and aft, and has a short segment which allows up and down flexation. The next joint is in-out (up down), as is the one after; the wrist has a short segment nearly identical to the hip, and the fingers extend radially. All fingers can be flexed side to side at the base, as well as in-out; the joint is a hinge. Every joint can be sealed if damaged.
Khizht are not the dominant species, per se, on their planet. They were locked in an evolutionary arms race until a few thousand years ago; their were in fact preyed upon by the semi-sentient Zht'ang, a xeno-therpod-dinosaurian, of similar size to velociraptor. Their development of technology vaulted them over the top, so to speak, and they have neither stopped nor destroyed the Zht'ang.
Khizht Culture predates sentience. Hives are established as communal child rearing facilities. Most children are male, females requireing special nutrition to form. Queens are not quite as territorial as most hive species. Khizht colonies are large, semi-underground affairs, built in and around living trees, and looking all the world like absolutely GIANT termite hills.
Khizht raise all young communally. A Khizht knows it's hive. Females, pre-sentience, would be chased away if too many were in the hive, and would then flee, possibly with a few males. Upon finding a suitable spot, or a hive with few females, would settle down and mate with any males nearby, who would then become brood sires, feeding the offspring, who then would be the workers.
Khizht sentience altered female behavior; females now are actively traded amongst colonies for general genetic spread. Authority is generally the eldest female, followed by male "Thinkers".
A Khizht egg is about 20gm. It needs watering, and a protein excreted by male workers, daily, until it hatches to a grub. It then needs a 30-50 pound carcass upon which to feed, as it grows to the larval stage. When it pupates to the larval stage, it becomes a semi-recognizable khizht, with an second abdomen of soft fleshy parts, in which to store additional fat until it can go through second pupation, and become an adult. this fourth body segment is absent entirely on adults, unless tramatically injured.
Khizht who lose a limb, or even their head, can regrow them if fed well; the fourth segment begins to grow, and they will then pupate again, repairing the missing limbs, and possibly altering gender.
There are three biological castes: Thinkers, Workers, and Females. Thinkers and workers are males; workers are not sterile, but also have no strong urge to mate. Caste is determined by what nutrients are fed DURING pupation; none is worker; high fat and/or protein produces thinkers; feeding by thinker puts hormones in that trigger feminine gender. Feeding is from a specialized gland, and the food is sprayed into the pupal cocoon, and collects at the botom, where it is sucked up by the pupa.
Larva and adults are both capable of speach, an learning peaks during the first year of adulthood, and continues for about three years. Larva, while mobile, seldom leave the hive, and have very poor mobility. (Larva are comparable to human infants and toddlers, intellectually and physically.) Larvae, if food is available, will eat 15-20 kg of vegetable and 5-15kg of meat, in order to put on some 3-4 kg, per week, until they reach nearly 3 times their post-pupal weight, then pupate, and emerge at full adult weight, having shed some. Language and basic mathematics are taught to larvae.
Adults are physically mature at age 1 year past second pupation. Mental maturity for workers occurs about age 2; after that, they tend to not learn much. Thikers never lose the learning edge. Females generally stop learning about age 2, but exceptions occur (especially post-trauma change...). If an adult repupates due to tramatic injury, the learning curve is reset.
Society still centeres around the hive. Each hive has a head queen, and a corps of her favored thinkers.
CT/MT sketch
Workers: Str2d+3, Dex2d-1, End2d+3, Int 2d3, edu 2d3, SS1d6
Thinkers: Str 2d, Dex 2d, End 2d+1, Int 2d6+1, Edu 2d6, SS1d6+4
Females: Str2d, Dex 2d-1, End 2d+2, Int 2d3, Edu 2d3, SS 9+1d
Notes: all have AV4 armor (Cloth).Penetrating damage (Firearms, stabbing weapons) does double damage to the thorax or abdomen, but not the limbs nor head.
Khizht can swim, and float, but they can not dive; their lungs are down the crest of the back.
First aid for Khizht is one level easier than for humans; all other medical care is normal difficulty. (First aid kits for Khizht are generally dermabond and sheet plastic). Khizht will bleed until surgury; if, however, the carapace is still sealed, the blood will be pulled back into the circulatory system...
Claws: the claws are Pen3, Damage 1, block 1.
Speed: 2 if on two legs; 3 if on 4.
Special lifting rule: if the lower arms are used as legs, encumbrance allowance is increased by 50%. If the lower arms are used in combat, an extra unarmed attack is allowed, at -2 to hit, but doing +1 damage.
0-G: Khizht suffer far less from 0-G than humans, taking twice as long to suffer health deterioration.
Atmosphere: Khizht are more tolerant to wide ranges of atmosphere due to not needing to move air in two directions. Halve all penalties. Also, Khizht can hold their breath twice as long as humans.
Vision: Khizht vision is 360 degrees, but is only binocular for 15 degrees straight forward. Their full vision has limited detail capability. within the 15 degree cone distances can be measured fairly well. The secondary eyes which are strongly detail capable, focus out to about 2m, and can see into the near IR and the Near UV, and have a 30degree cone. Khizht can not identify individuals visually past about 5m, and usually only wihtin the 2-3m of the secondary eyes.
Smell/Taste: is entirely on the antennae tips.
Touch: the khizht sense of touch is highly localized: Joints, hands and feet, plus antenae, palps and eyes.