Taming Cataclysm

You have to complete Taming Northrend before getting access to these quests!

Going through the quests which start at Audrey Burnhep or Varzok, one will encounter the following tamers:

Brok is located in Mount Hyjal. Coords: 61, 32
Pets (lvl 25, Rare):
Beast (Ashtail) - use Mechanical
Critter (Incinderous) - use Beast
Magic (Kali) - use Dragonkin

Bordin Steadyfist is located in Deepholm. Coords: 49, 57
Pets (lvl 25, Rare):
Critter (Crystallus) - use Beast
Elemental (Fracture, Ruby) - use Aquatic

Goz Banefury is located in Twilight Highlands. Coords: 56, 56
Pets (lvl 25, Rare):
Magic (Amythel) - use Dragonkin
Beast (Helios) - use Mechanical
Elemental (Twilight) - use Aquatic

The follow-up from Battle Pet Tamers: Cataclysm is Grand Master Obalis, where one has to defeat Obalis whom is located in Uldum. Coords: 56, 41
Pets (lvl 25, Epic):
Beast (Pyth) - use Mechanical
Flying (Spring) - use Magic
Critter (Clatter) - use Beast

Congrats on your achievement!

Brok - Mount Hyjal
Kali - Magic
Ashtail - Beast
Incinderous - Critter

Bordin Steadyfist - Deepholm
Crystallus - Critter
Ruby - Elemental
Fracture - Elemental

Goz Banefury - Twilight Highlands
Goz Banefury
Helios - Beast
Amythel - Magic
Twilight - Elemental

Obalis - Uldum
Grand Master Obalis:
Clatter - Critter
Spring - Flying
Pyth - Beast

Pretty sure Horde have the same kind of portals, but I'm speaking from an Alliance PoV. For the sake of speed, I took the Hyjal portal from Stormwind to battle Brok. Then I took the portal back to SW, and went into Deepholm to battle Bordin Steadyfist. Again, I took the portal back to Stormwind and went out to Twilight Highlands. After defeating Goz Banefury, again, I took the portal to and from Stormwind, this time to Uldum. After I defeated Obalis, I hearthed. This seems like the fastest way if you're looking to just knock out the achieve.

TL;DR - Brok-> Bordin Steadyfist-> Goz Banefury -> Obalis

For TomTom users:

/way Twilight Highlands 56.6 56.8 Goz Banefury
/way Mount Hyjal 61.4 32.8 Brok
/way Deepholm 49.8 57 Bordin Steadyfist
/way Uldum 56.6 41.8 Obalis