Certain fantasy archetypes are regularly used, for good reason. Everybody has an initial idea of elves and dwarves, so less explanation is required. The races tend not to get on, elves are graceful and slender with pointy ears and bows, whereas dwarves are short, stout, uncouth, tough and prefer axes.
They’re very well-known and can add variety to humans.
But why aren’t more intelligent races as common in fantasy?
There are a number that can be lifted straight from myths. Cyclops, centaurs, Amazons (admittedly, Amazons are human but can be classed as distinct, I think) all spring to mind.
One problem is that it can be hard to think of anything being quite so intelligent as a human without looking roughly the same (two arms, two legs etc). Dolphins, elephants and some birds are all very intelligent, but it’s hard to imagine them in a land-based civilisation.
An exception to this could be dragons. They’re a hugely persistent mythical creature, written of throughout history across just about every culture, and are still a favourite today. It’s really quite strange, as there’s no equivalent anywhere and even komodo dragons, whilst impressive, lack the wings (and fiery breath).
I’ve opted to have multiple races of humans. Neanderthals are the most famous example of this, but we have no real idea how homo sapiens and Neanderthals would get along together if they were not extinct.
The Felarians and Dennish are highly similar to each other and us (the main physical difference is the slightly darker Felarian skin). The Kuhrisch, however, are distinctly different. They’re very pale, have high resistance to the cold and are substantially stronger than their Felarian and Dennish counterparts.
The same issue exists in sci-fi, of course. I’d say there’s more freedom in sci-fi, though, as the technology level can make up for physical deficiencies or requirements (you can have a ship filled with water for an aquatic creature, for example), whereas fantasy tends to be pre-industrial, and it’s hard thinking of a Middle Age dolphin kingdom.