Iron Skyreaver

The Iron Skyreaver was bred for war by brutal Iron Horde beastmasters. Girded for battle in black steel and smoldering flame, and imbued with the blistering rage of the Iron Horde blacksmiths who gave it form, this monstrous chimaera suffers only the most fearsome of masters to ride it. Like a blazing comet foretelling doom and fiery destruction, hurtle down from the heavens upon this epic mount to herald your own campaign of conquest!

Unlike the mounts from the World of Warcraft Trading Card Game, this mount is directly purchasable from Blizzard. Released on January 16th, 2014, it is the seventh mount to be offered in this way.

Source
This item is available for purchase from the shop or the In-Game Store for $25 or €25. It was released on January 16, 2014.

Mount Journal
Iron Horde beastmasters bred this rylak for war and then girded it for battle in black steel and smoldering flame.

One of the most fearsome flying mounts the Iron Horde fields.
 * In-Game Store

Two heads are better than one - ''Bred for war by brutal Iron Horde beastmasters and girded for battle in black steel and smoldering flame, the monstrous Iron Skyreaver suffers only the most fearsome of masters to ride it. Like a blazing comet foretelling doom and fiery destruction, hurtle down from the heavens upon this epic mount to herald your own campaign of conquest!''
 * Blizzard Shop

Mail
Playered are mailed this mount by Mei Francis:

Presentation
With twin heads, jaws of steel, and dual afterburners strapped to its flanks, the Iron Skyreaver demands a sure-handed rider and a heathly dose of respect. Imbued with the blistering rage of the Iron Horde blacksmiths who gave it form, this menacing mount will drop from the sky like a fiery comet upon all who oppose its master. Take your rightful place on the back of this titanic terror, and feel the power of iron and fire! This is truly the mount of a conqueror!

Trivia

 * Though the mount is clearly themed after the Iron Horde from Warlords of Draenor, the mount was released well in advance of the expansion, before the Iron Horde had ever set foot on Azeroth.