Known issues: There might be random water appearing in the background.
Illustrious: Since "shark boy" has a tendency to generate shark tail. Try adding "no tail" in the prompt for full body shots and the like.
Pony: There are 2 versions of pony.
V1 gives off the style closer to the anime but unstable with chances to get multiple Beam or even sharks in the output.
V2 should be used with strength 0.7, has more stability.
I don't recommend using v1.