Pra & Mai was a package of coding found in Brawl, but was removed. It is believed to hold Plusle and Minun, from the Pokemon Universe. It is speculated that the pair might work like the Ice Climbers. But there was this Youtube video of hacked characters in Brawl.
Trophy
Plusle and Minun appear as a trophy. It is obtained by collecting all the Final Smash trophies. You need to hack your disc of "Super Smash Bros. Brawl".