Definitely the Heavenly Onyx Cloud Serpent from Sha of Anger. It’s such a low drop chance, but I’ve been dying to have it for so long, and clear him once a week on at least two of my 100′s, still hoping!
21:Best thing about the next expansion?
I gotta say that I’m most excited for all the Illidari/Illidan lore. He and his crew have been long-time favorites of mine, so I’m super pumped to see them doing things again.
It’s too easy to say the same mount as 10, so I’m gonna say that I think the coolest mount is the Ironbound Protodrake from the Ulduar meta achv. I got it back in MoP with a few friends, and it’s been a favorite of mine since Ulduar dropped!