Silverwind Larion

This gift of the silvery winds is only bestowed upon those that search high and low for the wisdom of Bastion.

Riding Requirements:

This mount is available to all eligible characters on your account.
Level 10
Apprentice Riding (ground)
Expert Riding (flying)

Source:

Vesper of the Silver Wind (treasure) in Bastion.

Notes:

This mount is contained within the Vesper of the Silver Wind, which is a treasure located at approximately 36, 25 in Bastion. However, it's not that simple! First you have to locate and collect 50 unique Anima Crystal Shards, which can be found at specific locations throughout Bastion. It has been reported you need to be level 60 to see these shards. The list of locations is too long to report here, but you can find them in the mount's this detailed comment on Wowhead. You should then speak to Forgelite Hephaesius will forge a Crystal Mallet of Heralds for you. The mallet will allow you to unlock the Vesper treasure.