While I was working on my Merman Ballister fic I was thinking of a little mermaid au with @mvjerbs oc and here's the cast
Ballister as Ariel
Ambrosius as Eric
Nimona as Sebastian/flounder (still a shapeshifer)
Grethyl (her oc) as Melody
Queen Valerin as Triton
Todd as Scuttle
Diego the squire (still a squire) as Grimbsy
The Director? Not sure if she's ursula but she's still an antagonist just still human, I think