How to perform
The player should use a character that has a Transformation Final Smash (making sure the other player has more points than the one who has the Smash Ball) and break the Smash Ball, wait until the time comes to 2 and then press B. If done correctly, the transformed character will appear alongside the winning player on the results screen. It can also be performed by waiting and the transformation running out as the timer does, but this is much harder to perform. The losing player will be able to move around the results screen, after the transformation runs out, and will drop to the ground. It is currently unknown if this glitch is possible on the 3DS version. This works on Bowser, Wario, Lucario, and Little Mac. It may also work on Charizard and Pac-Man.
However, due to a patch update, this no longer works