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.
These 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:
Fatalities and babalities for Mortal Kombat on Xbox 360
Fatalities and babalities for Mortal Kombat on PS3
Freddy Krueger’s Fatalities & Finishing Moves
Xbox 360
Tell’Em Freddy Sent Ya — Back Forward, Down, Down, X at any distance
Welcome To My Nightmare — Down, Up, Forward, Back, RT within sweeping distance
Babality – Back, Forward, Down, X at far distance
Stage Fatality – Forward, Down, Down, A at close range
PS3
Tell’Em Freddy Sent Ya — Back Forward, Down, Down, Square at any distance
Welcome To My Nightmare — Down, Up, Forward, Back, R2 within sweeping distance
Babality – Back, Forward, Down, Square at far distance
Stage Fatality – Forward, Down, Down, X at close range