Selkie

From fattwiki

In the past, the selkie was a witch who was killed by her village by being thrown into the ocean. After that, she traveled the ocean, taking treasure from every shipwreck, until the workers of the Veranda's casinos called to her.

After the events of The Cost of Greed, she bought a jewellery business on the Bluff City Boardwalk, which she now runs.

When the selkie is in her human form she looks like if Beyonce was Poison Ivy (with seaweed instead of plants).