Super Smash Bros. Brawl/Wolf

After playing through the subspace emissary once, return to the level where Pokemon trainer catches Ivyaur and Charizard (preferably with Jigglypuff or Metaknight). Play through to the part of the level where the spikes are coming out of the sides of the wall and your character is on a platform going downwards. After a few enemies, there will be a door on the left side of the screen, DO NOT GO THROUGH IT YET. Stay on the platform until the door is no longer visible, then fly or jump up and go in the door. Come right back out. The platform will be gone, but that's ok. Just fall all the way down, and go into the door to the left when you reach the bottom. Wolf O'Donell will appear. Fight him and after winning, he will be added to your roster.