If you ever wanted to have one of the Pandaren Elemental spirits as one (or even four) of your pets, you now can with Patch 5.1. However, you’ll only be able to pick up the quest once you have completed the entire Pet Tamer chain which currently ends with Grand Master Aki.
Just head to your Battle Trainer in your Pandaren capital city for the starting quest. For Horde, talk to Gentle San located at the top of the Shrine of Two Moons. For Alliance, talk to Sara Finkleswitch in the Shrine of Seven Stars.
Expect all four Pandaren Spirits to have level 25 Legendary pets including the corresponding spirit reward as part of the team.
Whispering Pandaren Spirit <Grand Master Pet Tamer>
Location: Exclamation Point, The Jade Forest (in the middle of Tigers’ Wood on a peak) – 28, 35
Pets: Pandaren Air Spirit (Elemental), Dusty (Flying) and Whispertail (Dragonkin)
Thundering Pandaren Spirit <Grand Master Pet Tamer>
Location: in the mountains above the Shrine of the Two Moons, Vale of Endless Blossoms – 67, 14
Pets: Pandaren Earth Spirit (Elemental), Sludgy (Magic) and Darnak the Tunneler (Beast)
Defeating all four Master Tamers will reward you with one of the elemental spirits as a reward as well as the achievement Pandaren Spirit Tamer.
Not surprisingly, once you complete the quest for the first time, you’ll be able to do it again as a daily which is account-wide, giving you a chance to get the other three from the corresponding elemental dailies – the Pandaren Spirit Pet Supplies.
On another note, Mumper confirmed that “the drop rates on Rare stones from battles are low. Pet daily quests offer a better rate but still not easy.”