Super Mario World: Vanilla Secret 3

For the most part, this secret stage is a calm one where Mario gets to ride on the backs of several cute and friendly Dolphins to get across the sea this level takes place over. They're still treated as enemies, however. Not because they can hurt Mario (they can't) but because Yoshi can eat them in the Japanese version of this game. I'm playing the American version where he can't do that, probably because eating dolphins doesn't translate really good, here. Oh well, at least I can still do that in the American GBA version...