I was always personally keen towards the minor differences of heavy-arcane using Highborn vs Kaldorei, despite the social differences.
Highborne
— Shorter ears
— Thinner eyebrows
— More lithe-like bodies, less packed on muscle.
— ‘Lighter’ complexions, such as white hair and tinted light-blue skin tones (Like a moth)
Kaldorei
— Thicker/longer ears
— Muscle-prone, more athletic like bodies
— More colorful, such as purple and green hair (I always thought more butterfly-like)
— Hairy
I know what I have to do, but I don’t know if I have the strength to do it …
…
Reposted because I’m lazy
Honestly, I’m not certain if we can consider the Manari skins as actual Manari Demons or just one of those ‘it was this way all along’ retcons from Blizzard, and Eredar had skin-tones ranging from greys to blues, reds and purples. Might just be the genes that expressed red melanin in the skin were also tied to other genes that gave the unlucky Eredar still trapped on Argus to survive the planetary Fel-infusion process.
We never saw any red Krokul, so maybe whatever gene is tied to that also acts as an adaptive mechanism for mutations, like what the Fel produces in most subjects. Considering the bulk of Draenei had purple, blue or gray skins, that would imply either a nocturnal lifestyle (camouflage) or that Argus had an unusually strong sun or something wrong with its ozone layer, resulting in the necessity of darker skin tones via melanin to protect against skin cancer and increase heat resistance.
More interestingly, many copper-based elements turn blue when combined with water and oxygen, and thus Draenei might have copper-based blood, resulting in their unique blue blood. Moreover, copper-based blood, known as hemocyanin, is commonly found in invertebrates and aquatic creatures, being more effective at transporting oxygen through the blood-stream and organs in low temperature, low oxygen situations. This could mean that Draenei evolved from water-based organisms in aquatic, arctic environments, and it would also explain the bulk of their males, given that in colder environments, the larger the body-mass the harder it is to freeze outright so long as the body’s core temperature remains the same.
This does cause some interesting problems once they left an aquatic environment, so we can assume that either Argus had a very low oxygen quota in the atmosphere, allowing the Draenei to out-perform rival or competing species who may have possessed more familiar hemoglobin blood-types, or perhaps the native species of Argus never incorporated iron into their cells, instead using a more abundant copper source instead. One of the reasons we have hemoglobin-based blood is theorized that life began around underseas vents, and on Earth, that translates into sulphur, zinc and iron being the more prominent metals and minerals found in samples dated to approximately this age in Earth’s progress.
It would also explain why the Draenei were this ‘Golden Age’ society. Hemocyanin is great for oxygen transferral in low oxygen density situations, but under-performs against hemoglobin in high oxygen density situations, so while the Draenei were still able to outperform rival species and predators, their energy levels would have been very low, meaning inter-species conflict would have been mostly display-based, or endurance-based, rather than the outright violence displayed by many mammalian species. This would have carried over into their evolution as from a species into a race, and we see it in Jed’hin Tournaments, where the basic move-set is grappling and head-butting, and tail-strikes and kicks are generally only permitted in high-level matches between skilled and experienced practitioners of this ‘ancient’ and ‘spiritual’ art. Furthermore, the Jed’hin restriction to be generally practiced only by males due to the necessity of having the bulk, physical endurance and the thickened cranial crests to survive the bone-shaking impacts of two massive Draenei colliding together, can possibly be traced back to old proto-societal contests for social dominance and control of the herd.
But how did they turn from sluggish quasi-aquatic creatures into the very active, intelligent and speedy people we see today?
Well … I’d argue they don’t have just hemocyanin as their blood-base. I’d argue that they also have nitrate, cobalt or sodium (salt is a metal, and I will smack somebody if I have to argue this point again!) as well as bacterial mechanisms in their lungs to help metabolise the process even further, resulting in a complicated immune system and biology, and also explain why they could jump world to world and have few issues, because their respiratory system can handle a wide range of oxygenated atmospheres with little issue as a result. High oxygen content, the nitrate/cobalt/sodium component kicks into gear and takes over. Low oxygen content, ye olde primitive copper-based part of the blood streams takes up the slack.
When we add magic on-top of all that, and the God-knows-how-long the At 'Amal Crystal was influencing their evolution, both physically and socially, I just … 
give up, I guess.
And that’s the end of my tangential ranting, carry on.
Most Mortal Races only use 10-12% of their brains at any one time. Gnomes use 15% and are constantly distracting themselves because this increase in intelligence also makes them uncomfortably aware of the world around them, at all times, and sensory overload is preferable to the ẁ̸͇͙̤͈̹͓̤̬͎̘̮̈́̈͒̀͘͜e̸̛̯̥̘̯̣͎̱̯͎͙̪̹̽̽͒̆̾̉͑̀̂̚͝i̴̮̐̒̈́̆͘r̸̠̍́̒͗̓̈́̈́̾͆̕͠d̶̫̺̰͍̿̎͝n̶͔̳̬̓͂͒̓͒e̶̛̗̯̺͍͈͑̇͗̏̀͑̽̚͘s̷̢̛̜̰̺̘̯̙̺̳͊̄̎́͌́͊͂̇͛͆̕s̷̼̐̐̋̒̍͌ going on around them at all time.
Kaldorei never actually kicked their arcane addiction and have been juicing with magical naltrexone from their Moonwells ever since. They’re still just as vulnerable to outside magical influences as their ‘derivative’ species, as witness with the Druids of Flame who have been imbued with Elemental Fire magic and have turned red and possess Fire-themed elements to their beings now, the same as Sin’dorei with the Wretched and Fel-Blooded, the Ren’dorei and the Shal’dorei being altered by the Nightwell.
Orc bones are actually a valuable source of iron, due to their Elemental Giant heritage. The darkness of their blood, often referred to as a dark red that’s almost black, is evidence of an extraordinarily high iron/oxygen content, which also explains the unnaturally herculean acts of strength they can often perform, they’re literally super-charged with dense muscles, hyper-oxygenated blood and a skeletal structure dense enough to resist concussions significantly easier than even other hyper-dense races, like Worgen, Draenei and Tauren.
Given the nature of the setting, I’d argue that the bones of Orcs, Ogres, Giants and, given their heritage, Humans of all creatures, probably have (to lesser or greater extents) bones where the structure of the bone is less a solid mass and more overlapping layers of lattices of bone, not only rendering the bone structurally durable, but much lighter than a bone of that mass should be, enabling them to move at significant speed compared to their bulk. The layers would also mean that unless victim of a staggering amount of force focused down to a small point, only a few layers of this lattice of bone-fibers would break at a time, but it would also mean that if enough layers were broken at one time, the bone itself would lose structural support and might take significantly longer to repair than a more traditional, ‘solid’ bone would.
Goblins that have access to a continuous and low-level supply of Kajamite are geniuses comparable to any Gnomish scholar, but access to the Kajamite-infused gas found in Zandalar has created a new breed of Goblin super-thinker. Given that the normal process of intake of Kajamite came in the form of a soda that delivered a short-lived burst of brilliance and wasted a lot of the Kajamite’s potential in the chemical effects of the drink, and then having to pass through the Goblin’s (or other creature’s) digestive tract to be absorbed, the gaseous version has several advantages in that once inhaled, it goes straight to the lungs and, from there, is added to the bloodstream along with oxygen as part of the oxygenation process of the bloodstream.
This means the Kajamite is directly added to the bloodstream, and will hit the brain within seconds without needing expensive alchemical alteration, bottling and preservation like the Kaja-Cola. Unlike the Kaja-Cola, this requires a significantly smaller dosage of Kajamite to produce the same effect, and will not lose large amounts of the mineral to the Goblin’s digestive system.
Getting pregnant normally makes you mode-locked unless you’re willing to yeetus the fetus. Druids are specifically warned against Wild-shaping if planning on a child, simply by dint of the fact that an Humanoid embryo cannot survive in the biology of a different anatomy, like say a bear or a cat.
While Worgen don’t suffer the same disasters when they change, there’s a risk of accidentally making the child a Worgen given that the process wherein the Gilneans were infected involved, at first, being bitten by a Worgen and then given the blood of said Worgen to allow the newly infected to retain their control. The validity of this is suspect, however, given that playable Worgen required a complicated ritual and the Scythe of Elune to maintain even partial control over themselves, but even then, Alpha Prime was the first true Worgen and may have had insights that allowed the Wolf Cult to function as infiltrators and saboteurs without losing themselves to the savagery of Goldrin, or at least for long enough for the infection of the Gilnean population to reach a critical point that the defenders could not resist an outright explosion of Feral Worgen from within their borders.
Despite this, due to the placental connection between mother and child, excessive ‘wolfing out’ can have unfortunate ramifications for the embryo, as while Blizzard has stated that the Worgen ‘curse’ cannot be transferred to the children of the Gilnean Worgen, the spiritual affliction could be, and might be amplified by repeated exposure at this most vulnerable state. This could result in a variety of outcomes, from a ‘natural’ shape-shifter, to a Worgen ‘Savant’ who can command or at least influence the Wolf-touched around them, to a child who possesses the natural ability to speak to and control canines and similarly related creatures, or might just be a very powerful Druid when they grow up.
Vulpera are a desert-dwelling species and probably possess a similar coat to a Fennec Fox, being thick, soft and relatively long, both to insulate them at night and to provide a barrier between their skin and the extreme heat of the daylight in an area devoid of cloud-cover and trees. They probably do not do well with wet, cold environments where their fur is rendered wet and cold for a long period of time. By contrast, Pandaren are depicted as coming from a wet, temperate area and probably do terribly in hot, dry climates where their bulk, fat reserves and single-layer coats probably leave them in a dire predicament.
That’s all for now, I must sleep.
This is probably confirmed in-game but Nightborne, being creatures of arcane, can use magic as easy as breathing. Any class will channel arcane into their discipline even on accident and must hone to keep it balanced, ie a hunter with arcane arrows or a warrior with arcane infused strikes.