I think the Harbinger of Flame is just awesome.
I love all his little spikes, deadly!
The companion pet comes from the Mark of Flame which drops from the boss Sulfuron Harbinger in the raid Molten Core.
He is part of the achievement Raiding with Leashes.
In the picture above, the Harbinger of Flame is under the effects of Papa Hummel’s Old-Fashioned Pet Biscuit. The biscuit doubles a targeted Non-Combat Pet’s size for as long as it remains at its master’s side. The biscuits are a common loot card from the trading cards. You receive a stack of 50 biscuits when you redeem the code and you can stack up to 250 biscuits. Get biscuits for your pets.