Deathlord's Vilebrood Vanquisher

The Deathlord's Vilebrood Vanquisher is the death knight class hall mount. It changes color depending on your spec.

Source
This mount is a reward from The Lost Glacier (quest).

History
Long ago, a great red dragon traveled to a Glacier to fight a great corruption. During the battle, the dragon fell to the ground dead and his remains remained there ever since

In present day, Amal'thazad and the Lich King have been perfecting a way to commune more easily with each other. The Lich King tells the lich to send the Deathlord immediately. The Deathlord races to the top of Acherus where a projection of the Lich King awaits him. The Lich King speaks of undead running towards the north of Icecrown on frozen ice in search of a great power. However, his vision does not reach as far.

The Lich King sends the Deathlord to investigate what is was and sends him to Northrend and shows him his vision of the undead rushing towards a skeletal dragon. At a dead end, the Lich King send the Deathlord to Wyrmrest Temple and question on of the bronze dragons. Finding Trizormu, the Deathlord suffocates him for avoiding to speak. Unable to take the pain anymore, Trizormu speaks of large glaciers that floated away from Icecrown. Not nothing anything else, Trizormu sends the Deathlord to ask Tariolstrasz. Asking the red dragon about the matter got the Deathlord kicked out of Wyrmrest Temple.

Not willing to give up, the Lich King tells the Deathlord to find information in the Ruby Sanctum. Arriving there, the Deathlord encounters the last brood of red dragons. At his own choice, the Deathlord decided the fate of the drakes. In their private tombs, the Deathlord find information about Kyranastrasz.

Knowing his prize and the location, the Deathlord travels north of Icecrown and is able to find the glacier. Walking through the fog while fighting undead, the Deathlord finds the body of the dragon. The undead around him have been feeding on his life energy. The Deathlord kills them and takes it for himself.

Using his unholy power, he raises the dragon into undeath, to serve as his mount for all eternity.

Mount Journal
A powerful red dragon raised in undeath by its own life energies, a true mockery of life.

Quest-line

 * Amal'thazad's Message
 * Frozen Memories
 * Draconic Secrets
 * The Lost Glacier (quest)

Trivia

 * There was an achievement for killing all the Red Dragons during the PTR called Unholy Determination.