Nereid

Nereids were a race of aquatic fey related to the tritons. Like the nymphs who lived in coves and streams, the dryads who lived in trees, and the oreads who dwelt in mountains, nereids were fey who were bound to the seas and oceans.

The Fishwives encountered a nereid near the Ancient Tomb's unsettling crevasse. They later encountered what appeared to be her severed head atop a tentacled body.