Triton

"Tritons guard the ocean depths, building small settlements beside deep trenches, portals to the elemental planes, and other dangerous spots far from the eyes of land-bound folk. Long-established guardians of the deep ocean floor, the noble tritons have gradually become increasingly active in the world above."


Tritons of Aneirys are something of a mystery, as none of their stories and legends seem to feature what we know as "vaults".

DnD 5e Wikidot Link:
Triton