Lore explanation
Elder Folk, otherwise known as Elds, are a race of humanoids hailing from ancient times.
A result of inter-species breeding, they're the result of a cross between humans and imps.
Their skin is usually fair, but varies in coloration between tribes, ranging from sickly green hues to fiery red.
The main characteristics of this race are their horns, skin, and long ears. Their body temperatures change depending on which area of the world they're from, being fairer in colder climates, and darker and more reddish in hotter ones.
Their horns are mostly vestigial, as they have adapted regular human forms of combat, forgoing their ancestral hand-to-hand combat abilities, and are now used mostly for aesthethic purposes, being adorned in much the same ways as humans do with their hair or ears.
Out of lore explanation
They're tieflings.