I've always heard this song associated with RAFFI (CAVOUKIAN), but the Harry Fox Agency (songfile.com) does not show him claiming rights to the song. There is a song by this name by STEVEN PULLARA, but I don't think it's the same song.
Is this song truly in the public domain? Whatever the case, it's one kids really love. I have to admit I haven't learned the song well enough to sing it without referring to a "cheat sheet" or to Rise Up Singing. I sure like it, though. I learned it about 15 years ago from Mary, who is now about 28 years old. She's mentally challenged, but she's a treasured member of the Sacramento Song Circle.

-Joe-