Crow
Source: Pet Battle. While smaller than the infamous ravens of Gilneas, crows are no less clever or cunning. Flying type. Just had a crow as secondary on live, they are not tamable as of this comment. Confirmed, they are now capturable.
Crow is a wild battle pet captured as a secondary pet on Darkmoon Isle by battling Darkmoon Glowflies at levels 5–10.
Guide awaiting review
Travel to Darkmoon Isle
Head to Darkmoon Isle and locate Darkmoon Glowflies that are level 5–10, as only that level range spawns secondary pets.
Battle Glowflies for Crow
Engage Darkmoon Glowflies and watch for a Crow to appear as a secondary pet — it is one of six possible secondary pets on the island, so it may take many battles before one appears.
Capture any quality Crow
Capture the first Crow you find regardless of quality, then use a Battle Stone to upgrade it to rare rather than spending hours farming for a rare-quality one — Battle Stones can also be purchased from other players on the Auction House.
Tips
Crow and Gilnean Raven both have Call Darkness synergy, but this combo does not work against Elemental-type pets because the blindness effect from Darkness is a weather effect and Elementals are immune to it.