For the achievement, you need the following pets:
- Grotesque
- Abyssius
- Fragment of Suffering
- Sister of Temptation
- Hyjal Wisp
- Chaos Pup
- Leviathan Hatchling
- Fragment of Anger
- Fragment of Desire
- Stinkrot
- Sunblade Micro-Defender
- Wretched Servant
Since the patch dropped and added these pets to the game, I've been farming Black Temple (and other instances) with my rogue to get the pets and to also have a chance at the legendary. It's my opinion that the best class for farming legacy raids is a rogue because of the speed boost.
I took a video of farming Black Temple, and it only took me around 17 minutes total. It'd be around 14 or 15 minutes if I didn't have to wait for so much talky-talk-talk between Akama and Illidan at the end.
Here's the video (I added some soundtrack music just for fun). The breaks you see in the video are because I haven't bought the software and it cuts me off occasionally, which means I have to restart the video mid-run through Black Temple.
(Yes, I know my key bindings are weird. I'm left handed and my key bindings are for my right hand while my left hand uses the mouse.)
Anyway, I hope you enjoy the video! I just made it for fun :)
I've farmed BT and Sunwell quite a few times so far. It's taking forever to get the Fragments. But they are REALLY cool pets! Take a look at the Fragment of Anger I got this week (click on the picture to make it bigger):
