Hey, the Obsidian Hatchling is one of the Raptor pets added 3.2. Unlike the rest, you can simply buy these for 50g. Well, on my server, Obsidian Hatchlings are selling for 200g on the AH. Basically, you're tricking people who don't know where to buy them. I've use different characters and made 5000g last week simply doing this.
The vendor name is Breanni and she is in Dalaran.
Enjoy. Post results!