To unlock the Puppet Master trophy in Mortal Kombat 11, you will need to play 25 AI Battle Simulator sets. The result doesn't matter, although winning will reward you with additional Koins.
You will also unlock the trophy below for playing 10 AI Battle Simulator Sets:
From the Main Menu > Fight > AI Battle
Pick three defenders, go to Find a Battle, choose your opponent, choose three attackers and start the match. Use the Touchpad to speed up to 4x speed. Once the fight is over repeat the steps above until you unlock the trophy.