Aqualea

From the Super Mario Wiki

Aqualea is a mermaid with a pink tail and blue hair, she has fins covering her gills where ears would be on a human. She is the boss of the eighth level in the Vs. Com mode of the SNES version of the game Wario's Woods. She is very bitter, vain and overconfident in her own abilities; she also believes that she is irresistible and that her competitors lose just to be able to face her again. She looks a lot like Meidou, another mermaid boss from the NES version of this game. It is unknown what, if any, connections the two have.