Optional tamer encounter tied to world quest Angry Residents in Stratholme Pet Battle Dungeon (all difficulties). Besides a strange located icon on the Zuldazar map that was removed later, on PTR there was no clue about this WQ being active when you were not in the scenario or even before completing Stage 6.
Also, the appearance of this guy was very inconsistent and I was locked to the challenge mode without Healing/Reviving pets, so I didn't have too much tries to check for reliability of my team (especially the Dust Bunny survivability). So please see this more as an idea than a foolproof strategy.
At least one of the pets for this strategy require the use of a specific breed.
The strategy offers a TD script that can be used with the TD Script addon. You can copy the script by clicking on the button to the left of the pets.