Patch 7.1 brought with it a new version of Raiding with Leashes: Part IV - Wrath of the Lich King
, but this time with a twist!
Once you collect (or get traded) all the pets for this achievement, instead of receiving a pet reward directly, you instead receive a Celestial Invitation
, which asks you to seek out Algalon the Observer himself.
It turns out he secretly tamed some super cute celestial pets and now you need to defeat him, with your own pets!
Once you defeat him, you will then finally receive your reward, which is the celestial bunny 星塵