Dolphin

Dolphins only appear in Vanilla Secret 3 and in a hidden area near the end of Chocolate Island 1. They are used as platforms to cross the water infested with Porcupuffers. They jump in and out of water either vertically or in parabolic arcs. They appear on the "enemy list", but are described as "not really an enemy", though it is said "they can take Mario the wrong way"   