Green Proto-Drake

The vrykul were the first to recognize their potential. Or maybe the second, depending on how you look at it.

Riding Requirements:

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

Source:

Mysterious Egg in Geen, Sholazar Basin. Requires Revered with The Oracles.
'Call to Arms' reward satchels (rarely)
The Black Market Auction House (rarely)

Notes:

You must be Revered with the Oracles in order to purchase a Mysterious Egg. After 7 days, the egg 'hatches' into a Cracked Egg which may contain this mount. Note, however, that you can also find this mount in the Satchel of Exotic Mysteries - which does not require you to be revered with the Oracles.