Mighty Caravan Brutosaur, comes with an unprecedented price tag of 5 million gold! You can purchase it from NPC:
[Horde] Talutu in Zuldazar.
[Alliance] Tricky Nick in Tiragarde Sound.
It will definitely get you noticed! It also carries two NPCs - an auctioneer and a merchant - making it uniquely useful as a portable Auction House.
Using illegal leveling and gold service might terminate the account!