The Micronax pet is a reward for completing the Glory of the Tomb Raider achievement. If you'd like this pet, but you're not part of a guild or group that's going for the achievement, I found an opportunity (referred by warcraftpets.com): There's a fellow named Neall on on OpenRaid (
http://openraid.zergid.com/) who organizes a wide array of instance-related achievement runs, including Tomb.
If you create an account on OpenRaid and do a search on #Neall, you'll see a list of his raids:
http://openraid.zergid.com/events/find#event_name=%23NeallHe plans his raiding schedule a couple of months in advance, and I've signed up for the Alliance-side Tomb Achievement raids as Winston. His raids are usually over-subscribed. I believe he takes the first 30 people to sign up, and I'm not among the first 30 (though I'm 31st for the June 2 raid).
But...
On the Horde side, the June 3 Tomb Achievements sign-up list has not yet reached 30. I've signed up as Grotar for Damage/Tank. (I'll tank if he asks, but I've noted that I've never tanked a raid before.) If you've got a Horde-side alt and you'd like the pet, this may be your chance; I certainly hope it's mine:
http://openraid.zergid.com/events/view/311530#roster