Perform a Babality on a boss character by executing the following tasks:

Goro/Kintaro
Play at Medium difficulty or higher and win every match (individual rounds are just fine, but no continuing).

Shang Tsung
Do not use the block button at all in the final round of the fight with Goro/Kintaro. Babality will automatically activate as soon as you win the match.

Shao Khan
Play at Medium difficulty or higher and do not lose a match. (individual rounds are just fine, but no continuing). Perform a Babality on EVERY character along the ladder, including Shang Tsung and Goro/Kintaro. Do not use the block button at all during the final round of the fight with Shao Khan. Babality will automatically activate upon winning the match.