Dryad

The dryad is a tree spirit in Greek mythology.

Information
These long-living dryads live deep in unpopulated forests. Their culture is known to be similar to Paleolithic humans, hunting and gathering various wild animals and plants, making "tree bark art", and simple tools. "tree bark figurines" have been found outside the forest, with no surprise, they resemble Venus Figurines.

Known to be timid or even hostile to outsiders, but they are especially hostile to their rivaling civilization, the Kodama.

Backstory
The backstory of the dryads are mostly unknown, because of how they have a unique language and their hostility/timidness towards outsiders.