Triton
From Ardrana
Tritons are rumored to be creatures from the Elemental Plane of Water that have been placed on the Prime Material Plane for some purpose unknown to man. They are sea dwellers, inhabiting warmer waters principally but equally able to live at shallow or great depths.
The lower half of a triton ends in two finned legs, while its torso, head, and arms are handsomely human. Tritons have a silvery skin that fades into silver-blue scales on the lower half of their bodies. Their hair is deep blue or blue-green. Tritons speak their own language as well as those of Sea Elves and locathah.
Note: Tritons originally appeared in this form in the 2nd Edition Monstrous Manual for the AD&D game from TSR. Their use here is for the purposes of providing context for the campaign only.