Looks like the new "boss" pets are on the PTR! Thought I'd make a thread showing what I've found so far. If you have anything to add, please do!
As shown in the pictures, the fabled pets have yellow paw prints above their heads instead of green, so they're pretty easy to spot.
![Image](http://img69.imageshack.us/img69/6327/bosspeticon.png)
You can currently fight them without being on the quest (though this may change). They seem to have normal pet moves, but are much stronger. Pets don't copy to the PTR at the moment so I couldn't properly test the battles.
![Image](http://img163.imageshack.us/img163/3087/nitunfite.png)
Now for the pets themselves!
Jade Forest:
Nitun
![Image](http://img708.imageshack.us/img708/5295/nitun.png)
Map Location:[url]http://img23.imageshack.us/img23/861/nitunmap.png[/url]
Ka'Wai (Credit to Petopia for the pic)
![Image](http://img717.imageshack.us/img717/6248/gorger.jpg)
Map Location: N/A
Valley of the Four Winds:
Greyhoof
![Image](http://img716.imageshack.us/img716/2655/greyhoof.png)
Map Location:[url]http://img7.imageshack.us/img7/9086/greymap.png[/url]
Kun-Lai Summit:
Kafi
![Image](http://img338.imageshack.us/img338/6582/kafi.png)
Map Location:[url]http://img823.imageshack.us/img823/8313/kafimap.png[/url]
Dos-Ryga
![Image](http://img40.imageshack.us/img40/3792/dosryga.png)
Map Location: [url]http://img708.imageshack.us/img708/9324/dosrygamap.png[/url]
Townlong Steppes:
Ti'un the Wanderer
![Image](http://img12.imageshack.us/img12/1301/tiun.png)
Map Location: [url]http://img195.imageshack.us/img195/4547/tiunmap.png[/url]
Dread Wastes:
Gorespine
![Image](http://img152.imageshack.us/img152/6963/gorespine.png)
Map Location:N/A
Vale of Eternal Blossoms:
No-No
![Image](http://img5.imageshack.us/img5/9370/nonox.png)
Map Location: [url]http://img827.imageshack.us/img827/5416/nonomap.png[/url]
Will update the thread as more info arises.