How do you unlock Jigglypuff in Super Smash Bros. Brawl?

Answer 1

There are a couple of ways:

Do 350 matches of brawls, then fight Jigglypuff and win in a brawl

Complete the Subspace Emissary, then complete Classic with any character (someone told me except Ike)

Complete Subspace Emissary, then events #1-#20, then fight and beat Jigglypuff in a brawl

Complete Subspace Emissary, then go on the stage "The Swamp" again. There will be a door (quiite late on) in there which leads to a brawl with Jigglypuff in Pokemon Stadium 2. Win, and you unlock Jigglypuff, and also add her to your Subspace Emissary Team.

Answer 2

2 ways: Beat the subspace emissary then return to the Swamp level and find a secret red door in the area where the barrel cannons are inside is Jigglypuff defeat it to have it join your team save the game then quit and you will unlock Jigglypuff or play 400 brawls and defeat Jigglypuff to unlock it.