Here is the third robot of the MM9 set, and the most popular by far; the amount of fan art I've seen of her even before the game was released is staggering.

Although the mermaid look is fairly predictable, Splash Woman looks pretty good for the first female boss of the classic Mega Man series (if you don't count the Copy Roll from Mega Man: Powered Up). If Tornado Man's design has a subtle reference to Harpuia, there is a more apparent similarity to Leviathan here, due to the trident and the helmet's shape. Still, her fighting style is fairly different and her weapon isn't ice related, so she manages to be unique in her own right.