Once you’ve completed the initial set of battles, the next round of tamers becomes available from Varzok in Orgrimmar. You can challenge these pet tamers of Kalimdor in a pet battle for increased XP, achievements and rewards. The quest is account-wide but faction-specific.
Defeating each pet tamer will give you a 5min Pet Recovery debuff, meaning you’ll have to wait out the 5min before you can battle the next tamer in the series.
The five pet tamers you need to defeat in Kalimdor are:
Traitor Gluk <Master Pet Tamer>
Location: On the right side of main path heading into Dire Maul
Level 13 Pets: Prancer (Critter), Glimmer (Dragonkin) and Rasp (Beast)
Grazzle the Great <Master Pet Tamer>
Location: Dustwallow Marsh – To the left of Ony’s Lair
Level 14 Pets: Blaze, Flameclaw and Firetooth (3x Dragonkin)
Kela Grimtotem <Master Pet Tamer>
Location: Thousand Needles – On a mesa, NW of Darkcloud Pinnacle
Level 15 Pets: Plague (Critter), Indigon (Critter) and Cho’guana (Beast)
Zoltan <Master Pet Tamer>
Location: Felwood – Just off the main path towards Jaedanar
Level 16 Pets: Beamer (Magic), Ultramus (Mechanical), Hatewalker (Mechanical)
Elena Flutterfly <Master Pet Tamer>
Location: Moonglade – By the lake (side of the flight masters)
Level 17 Pets: Beacon (Magic), Lacewing (Flying), Willow (Dragonkin)
Defeating these tamers opens up the quest to defeat the Grand Master of Kalimdor.
Stone Cold Trixxy <Grand Master Pet Tamer>
Location: Winterspring – Ice Thistle Hills, by old ruins
Level 19 Elite Pets: Blizzy (Flying), Tinygos (Dragonkin) and Frostmaw (Beast)
Defeating the Grand Master for Taming Kalimdor will unlock daily quests for all tamers on that continent (10 shots a day if you do them all).
Completing this chain allows access to the Outland series of battles.