Reins of the Albino Drake

Source
Albino Drake is a swift flying mount, and the reward for the Leading the Cavalry achievement.

Letter
The drake and the following letter from Mei Francis are immediately sent to players who complete the achievement:

Speculation
There has been some speculation that, due to the tinges of blue on various parts of its body, the Albino Drakes could have been some sort of creation of the Azure Dragonflight. In a way, the Albino flight could be seen almost like Malygos' version of the Chromatic and Twilight Dragonflights.

There is another possibility: They are focus of an unformed dragonflight, with very few individuals to form one. As exist other colors of the ancestral proto-dragons, like violet and white, still possible of some evolved dragonkin from proto-dragons of different colors. This open the possibility to types of unformed and/or incomplete dragonflights, such as the Violet Dragonflight.