The Edenaii are a small race whose pelt is the complimentary color to the color of their blood (blood colors can be just about anything reasonably achievable with RGB barring grey, black and white.)
These bipedal aliens are rather like crosses of wasps, rabbits, cats, fireflies and birds - small, fluffy things with glowstick-like luminescence glands behind their ears and along their limbs. They also have stingers, rabbit ears, feline tails and two pairs of eyes. Rarely, they will have insectoid wings of a strange soft wool-like texture. The venom in their teeth is actually a salivary enzyme, though still a very potent neurological toxin to humans. These creatures can develop one or more of several inherent abilities: changing their individual existence's ruleset from classical physics to quantum and back, using ESP powers, or using extensive training and an inherent mutation of the lungs to ACTUALLY RENDER THE BRAIN OXYGEN-INDEPENDENT.
This race is actually quite technologically advanced, having made machines that alter reality on a grand scale, sentient AIs and even particle-accelerating teleportals.
Their homeworld is a planet with many islands, most of which are claimed as territory by one caste or another. Different castes prefer different terrains: the psionics are very fond of tundra, forests and mountains, realitybenders dwell in deserts and savannahs, oxygen independents live underwater, workmen prefer stable and safe places like valleys, and winged live in high places...literally. Their caste's cities FLOAT. In the SKY.
Their race is a rigid, genetic-supremacy-based caste system, with the winged ones at the top as the ruling caste, the psionics and realitybenders as nobles, the oxygen-independents as minor nobles and those devoid of powers at the bottom.
However, the powerless workman/slave class does have an asset - regenerative gland mutations which allow them to self-heal at an incredible rate. An ordinarily grievous wound heals in mere days, and their immune systems are incredible. While this makes them the hardiest and least easy to kill class, it also means that the higher classes can and will brutally cull them using machinery to extract these glands for their own medical research purposes. Though hardy, these people do NOT have insane brute strength. That's a realitybender thing.
Realitybenders are less 'unkillable' because of the strain associated with altering the influence of physics on oneself, but are gifted with INSANE strength due to their constant hopping between realities and physical planes - enough to lift two hundred times their own body mass if they so wished it. For this reason, they are often warriors.
Psionics are likely the physically-weakest social class, possibly because the mental development needed to fully harness their capabilities is far higher than the physical and it follows that evolution would prioritize their brains because of that fact. Their main pair of eyes (as opposed to the secondary, smaller pair which is not so much a visual aid as a secondary sensory organ which is actually their main mode of identifying a lifeform's emotional processes, as they can't read behavioral cues) is often somehow malformed - blindness, farsightedness and astigmatism are especially common and almost exclusive to this caste, while nearsightedness is very rare. For this reason, eyepieces are considered a mark of the psionic caste, as only they would ever feasibly need them.
Oxygen-independents are harder to kill than psionics, and at an arguable advantage because of their (obvious) lack of dependence on oxygen. However, they lack intellect and are quite drunk with their own political power, which makes them greedy and opportunistic - ideal traits for Earth jobs such as banker, despite the fact that Edenai do not have the custom of storing everyone's currency in one place and in the custody of a certain group of people. That's just a stupid idea and would let these 'bankers' take all their cash, after all. They are the most corrupt and manipulative caste, and you should be thanking your gods that they're not the rulers.
Now, the winged are another story: they are neither easy nor hard to kill, but are blessed with the ability to fly and therefore nearly WORSHIPED in Edenai society as living gods because of their closeness to the sky. They are also capable of preforming many tasks that the typical Edenai could never even dream of and, because of this usefulness, became the highest caste over time - the head honchos, if you will. However, only a select group of winged ones is specifically considered high-caste, with the rest quite confusingly being dropped lower even than the powerless - this is because of the issue of blood purity, as only pure Winged rather than psionic or realitybending winged can be nobility.
Edenai culture is diverse among castes, and what is the highest honor to one may be a grievous insult to another - for example, Powerless culture dictates that you must refuse food twice when offered it, and then give in when asked a third time, while expecting a realitybender to adhere to these customs is suicide as they don't know the meaning of being refused anything at all. To broadly encompass the defining traits of each casteculture, however:
Powerless value honor and humbleness, realitybenders are proud and patriotic, psionics place heavy emphasis on knowledge and virtue, oxygen-independents are frugal and diplomatic, and Winged are basically groomed to rule wisely and well from hatching. However, all castes tattoo themselves in glowy dyes matching their blood colors and symbolising their clan or caste ideals.
Which brings us to their reproductive biology...
Their concepts of love and romance are a bit skewed, but basically there are five types they can feel and classify as love: love-hate between enemies, that which is unrequited, platonic love between friends, an official benevolent bond between two parties (closest to human love), and the bond which can form between apprentice and mentor. Typically, a partner is chosen based on a combination of individual attraction, previous experiences with said individual, genetic desirability and occasionally obligation, like a betrothal.
Their courtship is long and convoluted, as well as generally being limited to one's own caste, but they are considered married after they've mated - any ceremony surrounding that stuff is purely formality and good clean fun. Generally, hermaphrodites do not marry simply because there is no need, and neutrals adopt children rather than biologically parenting them if they do.
Edenai eggs laid at similar times and kept together will ALL hatch at the exact same time, despite the fact that some may not actually be ready to do so yet - for example, if you were laid on the seventh of October and I on the twelfth, we would still both hatch on the seventh of May - seven months after your having "happened", as is normal. I would be born as a 'lesser' being than you and given away to be raised in another caste, because hatching even a day early denies you certain genetic quirks which define a high-caste member. The 'deformity' is randomized, but an early-hatching Winged will generally be bumped down into the psionic caste due to their wimpy vestigial wings or even lack thereof and the presence of psychic powers (as in this example with you and me), while a workman who hatches early has every chance of being oxygen-independent or even rarely winged. The general rule is, early hatching is good among lower castes, unpredictable and frowned upon in the middlecaste, and absolutely a horrible thing in the high caste.
Lower-caste parents tend to be more devoted to their own offspring, as they lack even the concept of employing a nurse or similar figure to help with childcare.
I'm too lazy to type more at present, so that's all you get. To make one, use the feline build, whatever skin color you want, markings in a color that is the opposite of that skin color (the mark color is your blood color too!), mane and tail tip which complement the mark color (blue mane and green marks, for example), and any eye color. Grey and white are RARE skin colors, but they can happen.
