So, I know what a lot of people might say: mummies aren't really a race, they are just dead people that put a lot of bandage on them. But hear me out: 

Mummies would be one of the few races that would inhabit Desertic biomes. They're quite an old race and they are very civilized (not to the point of High Beavers but more than Elves) and quite specialized too (to the same extent than Elves more or less). But they would be a very extreme example of K-selected race: live very long, and have very few offsprings. 

But why would a specie would just roll themselves in toilet paper? Well, Mummies are a race of beings that fed on magic. Temporal magic, to be more precise. They "eat" time to gain magical properties, but the downside is the rapid decay of their body. Their minds are still alive and sharps, but the body quickly became unable to support it; and since a mind without a body is basically useless, they have to put all their body in bandages to still be able to work. 

Since they are basically immortal and they feed on time, they are very conservative and subject to high hubris. Quite like Elves, but more cunning and with more distrust towards strangers. 

It's just an idea I launched because I thought having desert-biome races might be a good idea. I might expand it later if I have more ideas on it. And don't hesitate to give feedback and expand it yourselves! 

I guess that is an interesting concept. Could you further elaborate on the "temporal feeding"? Does it have any effects on the surrounding areas? Are they just humans with inherit magical powers, or are they different? If not, what exactly do they look like?  It could be interesting if the way they live halts the growth of flora in the area, completely desertifying the area they live in.  They could be an interesting monster type race to interact with.

Well, the idea I had was kind of fuzzy because I only had the main concept but if ever I had to develop my idea (which is open to reinterpretation of course) it would be: 

1) A humanoid race, arising long, long ago and discovering how magic works, especially temporal magic

2) They used this magic to extend their life expectancy: they "accelerate" time around them (making all things to grow old quite quickly) and put it in their bodies to slow down the degradation process of their brains

3) Only their neural system pass time, but their bodies still decay, and they need their bodies, so they "embalm" themselves to keep the cohesion of their limbs (hence the "mummy" look)

4) Stealing time around them, nothing can live, explaining why they lives in the middle of deserts, because noone would care if sand lack suddenly a hundred of years. It will still be sand. It's ridiculously stable. 

Such a vulnerable civilization would likely find it very difficult to grow and develop in such a hostile environment, especially with a very small k-selected workforce. Elves have their speed and forests, dwarves have their brawn and mines, high beavers have their rivers and dams. What do mummies have to work with? Sand...?

However, their poor location would also give them access to a valuable asset that may make up for this weakness: r-selected races that are naturally forced into badlands by other k-selected races (such as orcs, goblins, or gnolls) would be a perfect source of a servant/slave caste to build their cities for them. Of course, they'd need to manage the dynamic very carefully since a slave revolt would probably be the end for the mummies, but the bedrock for a strong civ is there.