Being a hunter and a blogger, it would be remiss of me not to at least mention BRK's latest post. However, most hunter blogs would already have done this particular topic to death considering his popularity, and the internet really doesn't need another post about it.
So instead, I present to you one of my earliest screenshots:
It isn't THE oldest (I have a few from WoW beta), but it's the first to really show off my "oldest" pet - the one that has levelled with me from level 10 through 80 (although admittedly went through a slight skin change in Stranglethorn Vale); the one that has been to battlegrounds, Arena, raids and dungeons alike; the only one I'll never dismiss; and still one of the prettiest pet models around.
"BM spec since beta" would not have been complete without a faithful shadow to trail me, fight with me and die for me, and Shadow has done more for me than any other pet.
Here's a /salute to the kitties of the World of Warcraft; you most definitely Rhok.