Penguins: WoW Battle Pets
Select a pet:

Promotion: Northrend Heroic/Epic Upgrade
Bnet Shop: Classic

Vendor: Sairuk
Zone: Dragonblight
Faction: The Kalu'ak - Exalted
Cost: 12 (unlimited supply)
Vendor: Tanaika
Zone: Howling Fjord
Faction: The Kalu'ak - Exalted
Cost: 12 (unlimited supply)
TIP: You can filter pets in a wide variety of ways using the pet filters. You can even apply multiple filters to really zero in what you're seeking.