Several different races of intelligent humanoids are now considered native to the Underhill area, although evidence suggests that, historically, some of them may have immigrated from other cultures in prehistoric times. Generally, the native races can be divided up into two very broad subcategories of elementals and non-elementals.
The elemental races are similar to the traditional idea of "elemental spirits", although they are not inherently part of their racial element and may freely travel and live like other humanoids. Still, characteristics of their heritage are hard to miss. The common elemental races Underhill are:
- Dryads - elementally associated with wood and plants
- Naiads - elementally associated with water
- Oreads - elementally associated with rock and earth
- Salamanders - elementally associated with fire
- Sylphs - elementally associated with air
Significantly less common, but found in certain isolated regions of Underhill are:
The other three races lack a monolithic tie to any one element, although many Fae show elemental inclinations, and all of the races are, to some degree, interbred. Typically, certain memetypes seem to be more dominant, the kitsune and fae in particular, explaining for their significantly greater numbers. Typically, in terms of race, a child tends to take largely after one parent with traces reflecting the other; thusly, for example, a mating of a kitsune and a salamander is most likely to produce a kitsune who has a strong sympathy for fire and possibly a few minor traits related to her salamander heritage. Most kitsune and fae have at least some small amount of memetic heritage that traces to the other race, or an elemental foremother. Traditionally, so long as one can manifest the shift between fox and humanoid, Underhill society considers kitsune-crossbreeds as kitsune, while fae measure inclusion in their ranks by the presence of wings.
Children of two elemental types seem to take relatively randomly after one parent or the other, although mixtures are not completely unheard of, if rare. Most common are blends that show some mild intermixing, such as that the child of an oread and a salamander may turn out to be an oread with a strong affinity for heat-malleable metals.
The other races are
- Fae - Insect winged, humanoid women with pointed ears
- Kitsune - Humanoids with fox features and multiple tails, capable of transforming to full animal forms
- Avians - Bird-like, insular, and feathered humanoids; unlike fae and kitsune, they are fairly strongly associated with air, but less so than a full elemental would be. They Avians are extremely rare and are one of the few races that almost never interbreed with the others.
Historically, Yuriban races have included humans, although as a distinct race they became extinct in the wake of the Lilian Eruption. (Memetically speaking, it is likely that many natives have some trace of human heritage, although it is not dominant.) Some recent evidence has also suggested a possible existence of a race of oceanic women referred to as sirens, although details are hazy and it is suggested that if they ever existed, they would predate even the Lilians.