For whatever reason, I stumbled on this clip of a relatively old cartoon called The Wild Thornberries. http://www.youtube.com/watch?v=4y4a3ZTSGcs
Towards the end of the clip a “native” says that on full moons, river dolphins turn into humans and walk among the people.
Is this a real myth (/tall tale/story) that native people of Asia (South America?) really believe or is it one they just made up for the show?