In Mortal Kombat 9 for the PS3 and Xbox 360, doing fatalities is one of the best ways to destroy an opponent. It’s bloody, it’s humiliating, it’s everything you love to do to an opponent when you’ve beaten them to a pulp.
To do a fatality in Mortal Kombat 9, you must beat your opponent in the majority of rounds until it says “Finish Him”. At that point you’ll have a few seconds to get in the right position, and hit the proper button combination to perform the fatality you choose.
Fatalities do not have to be purchased or in your moves list in order to perform them, and once you perform any fatality at least once, it will be added to your moves list so you can refer back to it easily.
I have compiled full lists of fatalities for both consoles to make it easier.