There is a hidden quest that awards battle pet [npc=179083] during Kyrian Assaults in the Zovaal's Cauldron area of the Maw. You must find [npc=179083] during 3 different assaults.
The quest is unmarked. Locate [npc=179068]. She is smaller than an Ascended and has no wings. Look on the other side of the path across from Xandria who directs the assault. When you interact with [npc=179068] she will give you the buff [spell=353322] and a helper - [npc=179103]. This pink fox will travel with you and must stay alive.
[spell=353322] will allow you to see small blue paw prints that will lead you to [npc=179083]. Stay close to the last paw print. If the prints stop, take a few steps back then run forward just past the last print. More paw prints should appear. Be prepared to deal with some trash. The first time you find [npc=179083], the fox is curled up at the edge of rockface in a small flat blue ball that hardly looks like a fox. Click to wake up [npc=179083]. You can walk back uphill to [npc=179068] following the paw prints. (This seems to be optional.) [npc=179068] will say [npc=179083] likes you. That's all, no count appears on the screen.
After you've found [npc=179083] during 3 Kyrian Assaults, you'll receive the achievement A Sly Fox and will get your pet in the mail. See the comment by Mypciscraze for more details. A Sly Fox is one of 6 achievements needed for the meta-achievement On the Offensive. The meta-achievement lets you buy a covenant-specific mount from Duchess Mynx, the Death's Advance Quartermaster, in Korthia (coords 63.4, 23.4).
Mounts
Spoiler
Requires Exalted with Death's Advance faction and
On the Offensive. Cost: 1000 [currency=1767]
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