The Lake near the city

Near the city, there's a huge lake. In the lake resides a colony of mermaids, in elaborate houses carved into the bottom of the lake.

There are a couple hundred of them in the bottom. But these aren't exactly the ordinary friendly mermaids of fairy tales. Hundreds of years ago, some of Erebos's Dark creatures decided to play a joke on Meredith. She disapproved, and got pissed at them. So she turned them into half-fish, half-humans. But whenever they clomb out of the water, a warped form of their true selves are revealed. They are about 8 and a half feet tall, with grey skin stretched over their bodies, showing off their skeletons. Their eyes shift back and their mouth grows, changing into something like an angler fish's head on a humanoid body. Their hands and feet are webbed and clawed, and they can't move very fast, but they are deadly.

When they're in the water, their inherent nature is to be, well, Dark creatures. But some of them are decent.