Rhynraen-Anruth

The Rhynraen-Anruth ("Those Who Come From Beneath The Sea" in Umbraen Elvish) are a race of ocean dwelling humanoids.
They are said to have squid or fish-like features, particularly their heads, and fins and webbed hands and feet.
They periodically raid the Obsidian Shore and are feared by all the other races there.

The Rhynraen-Anruth leave the ocean only for short times indicating that they're at the very least semi-aquatic and need to be immersed in water to live.