This rare NPC is located in the Undermine at coordinates: /way 36.82, 78.17. Near it is a massive purple slime — its pet, which will also fight you.

Tip:

To make the fight with these enemies easier, use crowd control abilities. This will allow you to neutralize one of them first and then focus on the other. Note that killing the pet is not necessary — defeating the owner is enough to claim the reward.

Respawn: 20 minutes.