In Mortal Kombat 9 (2011 version) for the PS3 and Xbox 360, each character has multiple fatalities that they can perform at the end of the match if your opponent is defeated.
This is the list of all finishers (two fatalities, one babality, and one stage fatality) for Kratos.
All of these moves can be unlocked and added to your moves list by performing them in either Arcade Mode or Versus Mode.
Check out these complete fatality guides for more finishing moves:
Kratos’ Fatalities & Finishing Moves
Blade Of Olympus – Down, Down, Back, Forward, Triangle within sweeping distance
Medusa’s Gaze – Down, Back, Down, Forward, Square in jumping distance
Babality – Down, Forward, Back, Triangle in jumping distance
Stage Fatality – Down, Down, Down, X at close range