Ok,
I am an Alliance Druid. lvl 22.
I snuck all the way down to Wailing caverns, only getting killed once, to get the pattern for the Deviate scale belt and chest. One of them is a quest and one is bought from the vendor there. So I sneak in past all the Horde and deviate raptor things and by God I cant find the vendor.

Can anyone tell me the location? I really want to make the belt lol..

Kireth

Go up the mountain that is above wailing caverns and go down the sw side. There will be a grey stone area. If you change your camera view to where you're looking at the mouth of the entrance, it looks like a face. From that view, the eye on the left is where the vendor is. I dont know if allies can buy it there, but its worth a shot. Anyways, you have to drop down on the nose part of the stone, then drop into the eye part. It may take you a couple of tries, sometimes its not that easy. Hope this helps.