As the name would imply, this datapack allows you to steal other peoples dogs and cats.

In order to steal someone's pet you have to feed said pet Enchanted Steak (for dogs) or Enchanted Cod (for cats), which are obtained through trading with master level butcher and fisherman villagers respectively.

Upon stealing a pet a message will appear in the chat '[​thief] has stolen [​pet]!' which will alert other players as to what you are doing, on top of that the first pet you steal will grant an advancement 'Petnapper'.

Finally, in some villager houses there will be tamed cats/dogs that you can steal (this feature is namely for singleplayer).