(Side note: [...] indicates more will be added in time)
Information regarding standard Variants, their names, and common positions within Legions:
Zegus, Zegi (plural)
Nicknames:
Commander (fathers), overseer (mothers), trooper (young Zegi), military (a large group of Zegi).
Basic info:
Zegus were born as humanity's closest resembling cousins. Often viewed as a person's genetically older brother, Zegi are still very different from people. Being a lot taller (average adult height being 8 ft. or 244 cm. tall), a lot more aggressive when provoked, and surprisingly agile.
When pushed hard enough, Zegi can force themselves into transforming into any other Variant. The conditions just have to be right. There are no gender differences between the males and females.
Common positions:
Zegi are commonly placed as warriors due to their ability to wield most weapons perfectly fine. However, those that prove themselves to be worthy can exceed as higher ranking elites.
Types of known Zegi:
Standard Zegus.
Average Zegus appearance:
Smooth hair that reaches to the back of the head, mostly brown or black in color. Green, cyan, or light-yellow eyes. Most Zegi are a milky pale at birth, but their skin colors change as they mature.
They are very muscular, but still have that human-like look to them.
***
Feral, Ferals (plural)
Nicknames:
Neddy (fathers), Neddy (mothers), cub (young Ferals), pack (a large group of Ferals).
Basic info:
Ferals are the primitive hunters of Koroth. Using their quicker frames and lighter mass, Ferals can pose huge threats even if alone. They usually get picked on by Zegi and Thawed for being the shortest out of the three main Variants (standing at only 7 ft. or 213 cm. tall at full maturation).
In the wild, Ferals are most likely to form alliances with other packs to build mega-packs. Easing tensions between each other and securing the safety they need to reproduce and nurture their cubs. They are also the only other Variant to have a huge gender difference.
Most males cannot completely close their mouths, their jaws are too big. They also weigh a lot more and are used for a different type of hunting: Variant hunting. The females have retractable claws and smaller teeth. This lets them be the real ambush hunting predator each Feral aspires to be.
Common positions:
Due to their undying loyalty, Ferals will never accept the promise to move onto the next after their partners die, let alone their higher-ups. Ferals live and die loyal, making them great assassins and ambush fighters. Most Feral alphas become elites, letting them operate better.
Types of known Ferals:
Standard Feral, Scaler Feral, Deep Ocean Feral, Mountain Ascent Feral, Duster Feral...
Average Feral appearance:
Hair and eye color blend in to match their surroundings. Skin color is often dependent on their habitats. But when it isn't, they are mostly a tan-darker tan color.
Males have a permanent smile across their face thanks to their teeth, with a higher chance of receiving a vertical streak for their pupils. Instead of wearing full clothes, males choose either loincloth or pants.
Females don't look too similar aside from how they dress. They can switch to more traditional clothing or wear shorts and crop tops in order to fight off overheating.
They have one key feature that steps them apart from each other, males have extremely dense muscles. Females have the ability to get noticeable muscles but never to the same extreme.
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Thawed, Thawed (plural)
Nicknames:
Blizzard (fathers), hail (mothers), icicle (young Thawed), avalanche (a large group of Thawed).
Basic info:
Thawed the most religious and physically threatening out of all Variants. Towering over most others (9 ft. at full maturation or 274 cm. tall). However, they aren't very aggressive. Avalanche leaders are always named Prophets due to their connection with their mountains and their guardians. Oracles accompany Prophets in speaking with the Nine.
Despite their menacing appearance, Thawed are very religious and surprisingly careful. They worship mountains as idols and give their graces to the Nine Rules, while also respecting Zegi, Ferals, and Threshers alike.
Common positions:
Most Thawed are placed alongside the Zegi as warriors, but they serve as defenders instead of oppressive forces. Aside from that, Oracles are always sought after and welcomed to Legions for their unnatural talents. Prophets are also highly welcomed for their ability to perform rituals lower ranking Thawed cannot do.
Types of known Thawed:
Standard Thawed, Molten Thawed, Brittle Glade Thawed...
Average Thawed appearance:
Mostly pale colors represent them. Their hair is either a snowy white or a mystic blue, it also is the only other Variant to have short and neat hair. Thawed either have blue or icy blue eyes.
Prophets mostly use robes to cover themselves, which usually hold Thawed writing embedded into the material. Each letter is shared with the Oracle's prophets.
***
Thresher, Threshers (plural)
Nicknames:
Father (father), mother (mother), baby (young Thresher), family (a large group of Threshers (not to be confused with families as in bloodline)), Yonie (male), Yomie (female).
Basic info:
Threshers just exist with no real reason behind them. Sometimes, others joke about Threshers since they were an experiment that got out of hand. However, all other Variants agree on one thing: Threshers are surprisingly innocent and loving.
Males cannot grow higher than 5 ft. or 152 cm. tall. In addition to their short size, males cannot grow any meaningful muscles. Making them the weakest male by far. However, males possess several weird traits one might confuse for Third Rules. Such as the ability to produce light from their eyes, hair, and cheeks. And the heater organ, which generates enough heat to warm their bodies up by a surprising amount.
Females are wildly different from males. Being 6 ft. or 183 cm. tall, they can almost compete with some other Variants. They also get a lot more aggressive without their partners around and hold a keen overprotective instinct when with their partners.
Despite the differences, males and females heavily rely on each other. Without one, the other refuses to live. Often taking their own lives instead of living alone.
Types of known Threshers:
Standard Threshers, Mountain Threshers, Dense Canopy Threshers, Soft Sand Thresher...
Average Thresher appearance:
Both male and female Threshers get a faint green hue around their bodies from the chlorophyll they get out of tree roots. Both genders share shoulder-length smooth, neat hair.
Unlike the females, males always wear gowns or shorts without a shirt due to how easy it is to obtain those resources and the ability to breathe easier with them on.
Females choose tight, heavily layered attire depending on their environment and what predators lurk around. Whenever not wearing their outside outfits, females wear long pants with a cape covering their upper body.
***
Stages of life for every Variant:
Years 0-9, the foundations are set. Variants produce chemicals needed to support themselves later on in life. Hair and eye colors, and bulbs for teeth/claws begin to settle (except for Threshers).
Years 10-18, Variants begin to grow meaningful muscles. They start to move a lot more and show a willingness to become independent for brief amounts of time.
Years 19-30, changes start to settle. Zegi become competitive with each other, often fighting for fun. Most male Ferals begin to notice there is a growing gap between their lips, which grows as their teeth do until their lips cannot touch. Thawed begin learning basic rituals around this time. Threshers start to eat more fruits.
Years 31-41, instincts awaken. Natural instincts bloom in each Variant's mind. Along with these, knowledge like what languages they speak, role to play in their homes, who is the king of a continent, and other minor details naturally grow.
Years 42-59, more chemicals are produced to help their bodies. These chemicals serve to enhance their strength, height growth rate, remodel their stomachs, and prepare them for the next stage.
Years 60-70, reproductive instincts settle. Albeit not a must, Variants are encouraged to train themselves or each other on how to reproduce. If they don't during this stage, they lose the ability to reproduce later on in life because their bodies don't see a point in it. During this period, Threshers also start to change.
Years 71-81, the last touches are in place for all Variants. By now, Thresher babies look nothing like their parents. Changing seemingly overnight to fit their new set of genetics.
Years 81-400, real life takes control. Whatever happens after the age of 81 is due to the Variant themselves choosing it. Each Variant, no matter how healthy, dies after 400 years. However, there are some very special exceptions.