Magnaorbis has various sentient species. This is an explanation of each.
The term men, while also plural for males of their species, is the term mostly widely used for humans. While the term human is used, man (for singular uses) and men are the terms most commonly used (for both genders, with the gender specific terms of "man/men" and "woman/women" being in use only among the upper classes of New Britannia) in Magnaorbis' societies. Men are the largest sentient species in Magnaorbis and dominate its history, though have increasingly come, sometimes willingly, sometimes less so, to having to share it with the mer. While capable of using non-substantial aetherium, their abilities with it are markedly less than those of the mer and they are less proficient in the development of aethertech and the usage of some of its more advanced forms. They are also generally physically shorter than mer, often less intelligent and live shorter lives (nevertheless, in modern times, living to an average age of 230 if they are to die of natural causes and are unenhanced, though they previously lived far, far shorter lifespans), though they are stronger and more capable of athletic feats, have faster wound healing, mature faster and are more capable of building mundane (non-aetherium based) technologies. They ultimately overwhelmed the meric civilizations, who, without the still undiscovered advent of aethertech and their inferiority with mundane tech, were in a comparatively more primitive stage of civilization at the time. While the mer have come to be their equals, albeit now in a merged civilization as a result of the conquest of the mer, thanks to aethertech, many men still believe themselves to be superior to mer even if more educated classes think otherwise and their own rulers are demimer.
The term mer translates to "Elf", though that term has fallen into disuse and is of dubious acceptance in the meric community. It is unknown if the mer were created from humans (known as men in magnaorbis) or were formed from a different, albeit humanoid, race. Mer generally possess a greater natural ability with non-substantial aetherium, generally have a higher intelligence than men and live roughly two lifespans of men (which presently makes their average age of death by natural causes approximately 460, though until the 4th Era it was usually slightly under 200 but, like the lifespans of men, has been rising slowly but steadily since) when completely devoid of synth tech. As something of a "tradeoff", they, in spite of being on average physically taller than men, are physically weaker than men, have slower metabolisms leading to various downsides (the most serious of which being slower wound healing, though many of the more vain mer would say it is the issue of weight gain), take longer to physically and mentally mature and generally find it harder to create and work with mundane (ie non-aetherium based) technology, which stunted their civilization's development, allowing for their incorporation into New Britannia with lesser difficulty than other civilizations at the time. All the same, aethertech was predominantly a meric innovation, resulting in their species being credited as being different, but equal, to men by many scholars, even if tensions between the two races remain existent in common society.
The term demimer translates to "Half Elf", though a translation more accurate to their nature is "Part Elf". The term is truly vague, and technically, as a result of their interbreeding over the centuries, nearly all men and mer could technically said to be demimer. Nevertheless, demimer are those who manifest a combination of traits from men and mer. This obviously means that they have an ancestry in both races, though it is possible for a "pure" mer or man to be born to a mixed couple, or even for two demimer to produce a "pure" stock, just as two "pure" mer or men with sufficient mixed ancestry could produce a demimer and (very, very rarely) an offspring of the opposite race, though these latter two instances are a rare occurrence and only occur when one or both parents, while "pure" themselves, are not sufficiently distanced genetically from their mixed ancestors. Demimer were once scorned by mer as being abominations and men as being the product of race traitors. However, as the demimer rose to prominence, with the royalty and nobility of New Britannia themselves intermixing with mer (to the point that soon thereafter most of the upper class was demimeric in nature), they gained increasing acceptance by men, and as the variation of their genetics became clear (with some being more like men, others more like mer, and others truly in between), the mer began accepting those with predominantly meric attributes. Eventually the demimer, in spite of their race's broad variations, were formally recognized as a distinct race with equal status in to men and mer (after a time of being treated as either men or mer) largely as a result of their predominance in the upper echelons. As stated previously, some demimer are more like either men or mer than a true blend, though such is also quite common as well. Some appear very meric but have the lifespan and aetherical inclination of men and vice versa, while others are more in the middle in all regards or some regards.
While the general public has been lead to believe that there are no such thing as sentient sheep, in reality, presumably because of aetherium exposure, there are indeed sentiment sheep, usually unnaturally colored. The mascot and namesake of CocoCorp, Coco the Blue Sheep, is widely said to merely be a fictional character seen as a result of hallucinations (that some link to the mercury content of Chromola). In actuality, while many sighting of him are indeed hallucinations, Coco does in fact exist and, while for obvious reasons he is not the official head of CocoCorp, he is unofficially its leader. Little is known about the sentient sheep, even in circles aware that they truly exist, though some have suspected that they are agents of Omorthan Sheol and are among the only things still in direct contact with him.