I hear you. Mixing and matching is the way to go around here, honestly.

Oh, I didn't even think about doing anything other than full blown mermaid. What you're doing with Jim sounds great, and I think I'll do something similar. I'd also like to bring up that dolphin's have prehensile dicks... Nature's amazing.

And you know what, Spock is absolutely going to have a slightly bigger monster D with several ridges and a few scales. Science is also amazing.