Pets with Unique Ability Sets

Drop: Supremus [??+]

Zone: Black Temple

Approximate Drop Rate: 1 in 33

Drop: Time-Lost Wallet

Zone: The Deaths of Chromie Scenario

Approximate Drop Rate: Unknown

Vendor: Draemus

Zone: Dalaran (Broken Isles)

Cost: 200 (unlimited supply)

Quest: Crysa's Flyers [1]

Zone: Northern Barrens

Drop: Torn Sack of Pet Supplies

Approximate Drop Rate: Unknown

Pet Store 

Achievement: Raiding with Leashes V: Cuteaclysm

Category: Collect

Profession: Archaeology - Arakkoa

Artifact: [Ancient Nest Guardian]

Pet Battle: [17-18] Winterspring

Drop: Emperor Vek'lor [??+]

Zone: Temple of Ahn'Qiraj

Approximate Drop Rate: 1 in 10

Pet Battle: [17-18] Deadwind Pass

Pet Store 

Vendor: Sylvia Hartshorn

Zone: Val'sharah

Faction: Dreamweavers - Revered

Cost: 500 (unlimited supply)

Drop: Leafmender [90]

Zone: Timeless Isle

Approximate Drop Rate: 1 in 33

Quest: Adopting the Adorable [98]

Zone: Val'Sharah

Drop: Golemagg the Incinerator [??+]

Zone: Molten Core

Approximate Drop Rate: 1 in 14

Pet Battle: [25] Timeless Isle

Vendor: Draemus

Zone: Dalaran (Broken Isles)

Cost: 100 (unlimited supply)

Drop: Crane Nest

Zone: Timeless Isle [90]

Approximate Drop Rate: 1 in 50

Vendor: Ransa Greyfeather

Zone: Highmountain

Faction: Highmountain Tribe - Revered

Cost: 500 (unlimited supply)

Promotion: Overwatch Origins Edition and Collector's Edition

Vendor: Mei Chele

Zone: The Wandering Isle (Monk Order Hall)

Cost: 1000 (unlimited supply)

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

Drop: Siegecrafter Blackfuse [??+]

Zone: Siege of Orgrimmar

Approximate Drop Rate: 1 in 125

Drop: Shannox [??+]

Zone: Firelands

Approximate Drop Rate: Unknown

World Event: Midsummer Fire Festival

Vendor: Midsummer Merchant (Horde) / Midsummer Supplier (Alliance)

Cost: 350 (unlimited supply)