Kalimdor Tamer

I wasn't sure if anyone would need a list like this. I made it cause I was hoping from one website to another. I hope this helps some one.

Eastern Kingdoms Tamer:

Arathi Highland: LVL 7 Battle Pets
Blasted Lands: LVL 16 Battle Pets
Cape of Stranglethorn: LVL 9 Battle Pets
DuskWood: LVL 5-6 Battle Pets
Elwynn Forest: LVL 1-2 Battle Pets
Ghostlands: LVL 3-5 Battle Pets
Hinterlands: LVL 11 Battle Pets
Northern Stranglethorn: LVL 7-8 Battle Pets
Searing Gorge: LVL 13 Battle Pets
Swamp of Sorrows: LVL 14 Battle Pets
Twilight Highlands: LVL 23 Battle Pets
Westfall: LVL 3-4 Battle Pets
Badlands: LVL 13 Battle Pets
Burning Steppes: LVL 15 Battle Pets
Deadwind Pass: LVL 17 Battle Pets
Eastern Plague Lands: LVL 10 Battle Pets
Eversong Woods: LVL 1-2 Battle Pets
Hillsbrad Foothills: LVL 6 Battle Pets
Loch Modan: LVL 3-5 Battle Pets
Redridge Mountains: LVL 4-5 Battle Pets
Silverpine Forest: LVL 3-5 Battle Pets
Trisfal Glades: LVL 1-2 Battle Pets
Western Plaguelands: LVL 12 Battle Pets
Wetlands: LVL 3-5 Battle Pets

Kalimdor Tamer:

Teldrassil: LVL 1-2 Battle Pets
Azuremyst Isle: LVL 1-2 Battle Pets
Darkshore: LVL 3-5 Battle Pets
Durotar: LVL 1-2 Battle Pets
Felwood: LVL 14 Battle Pets
Mount Hyjal: LVL 22 Battle Pets
Northern Barrens: LVL 3 Battle Pets
Southern Barrens: LVL 9 Battle Pets
Tanaris: LVL 13 Battle Pets
Uldum: LVL 23 Battle Pets
Winterspring: LVL 17 Battle Pets
Azshara: LVL 3-5 Battle Pets
Bloodmyst Isle: LVL 3-5 Battle Pets
Desolace: LVL 7-8 Battle Pets
Dustwallow Marsh: LVL 12 Battle Pets
Feralas: LVL 11 Battle Pets
Mulgore: LVL 1-2 Battle Pets
Silithus: LVL 16 Battle Pets
Stonetalon Mountains: LVL 5-6 Battle Pets
Thousand Needles: LVL 13 Battle Pets
Un'Goro Crater: LVL 15 Battle Pets

OutLand Tamer:

Blade's Edge Mountains: LVL 18-19 Battle Pets
Nagrand: LVL 18 Battle Pets
Shadowmoon Valley: LVL 20 Battle Pets
Zangarmarsh: LVL 18 Battle Pets
Hellfire Peninsula: LVL 17 Battle Pets
Netherstorm: LVL 20 Battle Pets
Terokkar Forest: LVL 18 Battle Pets

Northrend Tamer:

Borean Tundra: LVL 20-21 Battle Pets
Dragonblight: LVL 22 Battle Pets
Howling Fjord: LVL 2021 Battle Pets
Sholazar Basin: LVL 21 Battle Pets
Zul'Drak: LVL 22 Battle Pets
Crystalsong Forest: LVL 22 Battle Pets
Grizzly Hills: LVL 21 Battle Pets
Icecrown: LVL 22 Battle Pets
Storm Peaks: LVL 22 Battle Pets

Pandaria Tamer:

Dread Wastes: LVL 24 Battle Pets
Krasarang Wilds: LVL 23-24 Battle Pets
Townlong Steppes: LVL 24 Battle Pets
Valley of the Four Winds: LVL 23-24 Battle Pets
Jade Forest: LVL 23-24 Battle Pets
Kun-Lai Summit: LVL 23-24 Battle Pets
Vale of Eternal Blossoms: LVL 24 Battle Pets

When an area doesn't get ticked off (or gets 'green') when you have captured a pet, simply log off and back on again. Reloading doesn't seem to work.

As of 5.2 Horde players can Access Teldrassil by flying to Stormwind Harbor, then aboard 'The Bravery'. This boat takes you to the south shore of Teldrassil. Make sure to capture a [npc=62242] since it's only found there!

After checking Teldrassil in the achievement, you can return to the docks in Ruth'eran village (52, 90) and aboard 'Elune's Blessing' to get to Azuremyst Isle from where you can get to Bloodmyst Isle. Note that you can't fly on/between those two isles, but swimming from Azuremyst to Bloodmyst won't trigger Fatigue.

Bloodmyst Isle is [npc=62051]'s only home and therefore it's a good choice to go looking for.

Lucky hunting!