Pet Manager Cooper:
Sure there is a way, but it won't be easy.
The Pet Manager Association has recently learned that the villain we tracked down was actually a member of a petnapping ring. We've been able to track one of the other members. His name is Atingo.
The creatures that Atingo had stolen have practically turned into monsters. But if you kill him, all the pets he's tamed will have no owner. I don't know how he managed to lure them away from their previous owners and made them his slaves. To free the creatures from this unnatural bond you will have to kill them as well, even though I'm not a fan of this solution.
If you kill the pet that has been stolen after the death of its current ownver, you will put an end to their terrible bond and the soul of the creature will surely rest in peace.