Hamadryad

Hamadryads are tree nymphs similar to dryads, but the books do not establish whether they are a separate kind of tree spirit or simply dryads with a synonymous nickname. In Greek tales, they are sometimes thought as the nymphs of oak trees, or as dryads who simply live in their trees, but are unable to leave, or as the dryads who die with their trees. One Hamadryad named Oak was a member of Aslan's council in The Magician's Nephew.