The Grinder Companion Pet is one “rocky” little dude!
The pet comes from Imbued Jade Fragment which is a rare drop from the Pandarian champion Karr the Darkener. Karr can be found in Dread Wastes (approximate coordinates 71,37).
In the picture above Grinder, the pets are under the effects of Papa Hummel’s Old-Fashioned Pet Biscuit. The biscuit doubles a targeted Non-Combat Pet’s size for as long as it remains at its master’s side. The biscuits are a common loot card from the trading cards. You receive a stack of 50 biscuits when you redeem the code and you can stack up to 250 biscuits. Get biscuits for your pets.