Armadillo Pup
Sold by Critter Kill Squad. Rolls into a protective ball when it feels threatened. Or when its mother calls. Critter type. Curiously enough, this pet has 2 different breeds although he's unique, making a player only able to have one of them.
The 
Armadillo Pup is a critter battle pet purchased from your Guild Vendor after earning the Critter Kill Squad achievement.
Guide awaiting review
Earn Critter Kill Squad achievement
Kill 50,000 critters across Azeroth to earn the Critter Kill Squad achievement.
Reach Exalted guild reputation
Increase your guild reputation to Exalted rank.
Purchase from Guild Vendor
Visit your Guild Vendor and purchase the Armadillo Pup for 
300 Gold after your guild has achieved Critter Kill Squad.
Tips
The item you purchase is rare quality, but it summons an uncommon green pet. Use a Flawless Battle Pet Stone if you want to upgrade it to rare quality.
This pet exists in two different breeds, and you can only obtain one of them per character.
