King Dice seems like he'd only want the best of everything, so it'd make sense he'd want the most perfect woman even if she happens to be a mermaid. I just, I dunno, man, I think they would work well together.
And no, I don't ship them based on looks alone, so you can't accuse me of shipping them because they're the two most popular and attractive male/female characters. I know it's a really cracky ship, but I do like it. I love them so much, you don't even know.
King Dice x Cala Maria ((This was actually the first ship I ended up loving in Cuphead, and by god did I fall for this one hard.