Sea Monster Princess

A sea monster is not a mermaid, and keeping those two apart is what makes this one work.

Mermaid design is pretty: bright scales, long hair, a shell or two. Deep-water monster design is the opposite, built on things that live where there is no light. Drained colour, translucence, fins that look functional rather than decorative, and a general sense that this creature would be unsettling up close.

Push it in that direction and the princess half becomes interesting, because royalty on something genuinely strange is a much stronger picture than royalty on something cute.

From the Starsue monster princess set.