Playing with genetics- Movie style

I'm entering a contest where you create Movie character sand then you "play with genetics" to get a an offspring.  Pretty cool, right?

First up, The Little Mermaid ala Disney.

Land-loving Ariel

Prince Eric Cumberbeach

 Adorable offapring as a Young Adult:  Rosie

Stranginly, she does not wish to be part of your world and wishes to become a mermaid...