Dryads are fey creatures of the forest, each bonded to a specific tree, in the form of beautiful (albeit woody) elfin women who benevolently protect forests and woodlands.
Further reading: https://dungeonsdragons.fandom.com/wiki/Dryad
Hamadryads
A hamadryad is a more powerful dryad bonded not to one tree, but to an entire forest. Hamadryads fiercely protect their domains, helping their bonded ecosystem to thrive, and working to destroy or repel any threats.