I just spotted a preview video on YouTube of the new Gregarious Grell pet. The video is pretty short and the music may not be to everyone's liking, but it shows off some of the Gregarious Grell's animations and gives a nice preview of how this pet looks and behaves in-game.
The Gregarious Grell pet is a brand new pet offered through the WoW TCG, and it's the first Grell pet available in WoW. Vicious Grell loot cards (which you redeem for this cool pet) are pretty common, so they're not that expensive. If you want more info on this new pet, or to see a few current ebay listings for the Vicious Grell loot card, then pop on over to the Vicious Grell loot page.
Gregarious Grell Preview Video