They are the same person. The only reason why they changed the name here in the U.S. and/or eurpoe is because in Japan, he was always known as eggman. They changed it so that it would be the same name around the world.
I do agree, it was an awsome show. I saw on Cheatcc.com, they have the amount of vs. matches you need to unlock people, and Jigglypuff is third to last. I'll go look and post the info in a min.