Pets with Unique Ability Sets

Pet Battle: [17-18] Winterspring

Drop: Emperor Vek'lor [??+]

Zone: Temple of Ahn'Qiraj

Approximate Drop Rate: unknown

Pet Battle: [17-18] Deadwind Pass

Drop: Golemagg the Incinerator [??+]

Zone: Molten Core

Approximate Drop Rate: unknown

Drop: World Drop

Zone: Winterspring [50-55]

Approximate Drop Rate: 1 in 10,000

Promotion: Starcraft II: Heart of the Swarm Collector's Edition

Pet Battle: [3-6] Silverpine Forest

Pet Battle: [10-11] Western Plaguelands

Vendor: Halpa, Naleen

Zone: Mulgore - Thunder Bluff

Cost: 50 (unlimited supply)

Pet Battle: [23-25] The Jade Forest

Achievement: Littlest Pet Shop

Category: Pet Battles

Drop: Chromaggus [??+]

Zone: Blackwing Lair

Approximate Drop Rate: unknown

Pet Store 

Pet Battle: [18-19] Nagrand

Vendor: Paul North

Zone: Orgrimmar

Cost: 30 (unlimited supply)

Vendor: Quackenbush

Zone: Stormwind City

Cost: 30 (unlimited supply)

Profession: Archaeology - Dwarf

Artifact: [Clockwork Gnome]

Pet Battle: [24-25] Townlong Steppes; [24-25] Dread Wastes

Pet Battle: [18-20] Blade's Edge Mountains

Promotion: Authenticator Account Link

Drop: Magmadar [??+]

Zone: Molten Core

Approximate Drop Rate: unknown

Profession: Archaeology - Tol'vir

Artifact: [Crawling Claw]

World Event: Hallow's End

Quest: The Creepy Crate [10] (Alliance)/(Horde)

Pet Battle: [1-10] Darkmoon Island

Pet Battle: [17-18] Winterspring

World Event: Children's Week

Quest: Back To The Orphanage [75]