Elemental Drakes are epic flying mounts that were introduced in World of Warcraft: Cataclysm. They represent elemental powers: stone drakes are the earth elementals in a dragon shape and storm drakes are the aspects of air.
Elemental drakes as loot
[Reins of the Drake of the North Wind] is a rare drop from Altairus in The Vortex Pinnacle dungeon.
[Reins of the Drake of the South Wind] is a rare drop from Al'Akir - the last boss of Throne of the Four Winds raid.
[Reins of the Vitreous Stone Drake] is a rare drop from Slabhide in The Stonecore dungeon.
[Reins of the Phosphorescent Stone Drake] is a 100% drop from Aeonaxx - rare spawn in Deepholm.
Elemental drakes from Achievements
[Reins of the Drake of the East Wind] is obtained as a reward for completing the achievement [Glory of the Cataclysm Raider].
[Reins of the Volcanic Stone Drake] can be obtained by completing the achievement [Glory of the Cataclysm Hero].
Purchasable Elemental drakes
[Reins of the Drake of the West Wind] can be purchased from Pogg <Hellscream's Reach Quartermaster> or Quartermaster Brazie <Baradin's Wardens Quartermaster> for 200 . Requires exalted state with Hellscream's Reach or Baradin's Wardens.
Crafted Elemental Drakes
The Sandstone Drake is obtainable through the Alchemy created item [Vial of the Sands].
Phosphorescent Stone Drake