Sweet post, It reminds me of a great idea I had for an exotic adult entertainment venture,

'Strippers with Flippers,
Mermaid Burlesque'

Basically topless women in your pool with fish bottoms, if they want to Ariel that's their problem. Could work for mermen as well, though they prefer to be called seamen.

Narwhals are just unicorns right, ones that fell in water and paddled till they wore their legs to finny nubs.