you have to unlock all the events and one of the events unlocks jigglypuff
Be Jigglypuff And Pikachu In Adventure Mode
clear adventure mode
complete adventure with pikachu and jigglypuff
Jigglypuff - Clear Event Mode.
Hold Up then press B.
In SSF (Super Smash Flash) you must play as Pikachu on Adventure Mode on Very Easy and then defeat Jigglypuff to unlock him.
No, but he is in Super Smash Brothers Brawl.
you need to do adventure as pikachu and jigglypuff
you can unlock jigglypuff by doing event number 10
He is not playable in the game
Super Smash Flash is a flash version of Super Smash Bros. It is not an official version of the Super Smash Bros. series.
If you mean a Poke'mon trainer, then no. The playable poke'mon are Pikachu, Mewtwo, and Jigglypuff if I'm correct.