Homebrew Bone fairy Species Details

a race of humanoids that call themselves bone fairies, thrive in dark spaces.

Shorty after being born the bones of bone fairies grow to piece the skin and warp the tissue of the fairy sometimes it could be as small as having bone freckle the face or patch in small formations to being as bad as large bone spikes as shoulders and extra rib cages outside the body. 

They feed on meats and some plants but mostly the bones of creatures. They enjoy dark places and live in generally dark places like caves or mountain caverns.

Bone fairy Traits

racial traits of the bone fairies include

Dark vision

bone fairies can see 60 feet in darkness.

ability score improvement

bone fairies gain +1 dexterity, constitution and wisdom.

languages

bone fairies can speak primordial and some common as well 

Bone entombment

Once per short rest, as a reaction when you take damage, you can entomb yourself in bone, which breaks away at the end of your next turn, gaining temp HP equal to half your current level x 10. After you take the damage, you gain vulnerability to cold damage, your speed is reduced to 0, and you are incapacitated. All these effects end when the bone bone breaks away.