Here's a rundown of its abilities:
The Crow's skillset revolves around Flying-type abilities, but let's take a closer look at the outlier. The Humanoid-type ability Call Darkness is strong against Dragonkin, an advantage most Flying pets don't have. But the ability's strong point truly lies in its debuff. Initially, Call Darkness seems like something that might work against your own team, but don't be fooled!
Call Darkness is a powerful weather effect that deals a decent amount of damage up front, while rendering all pets Blinded and reducing all healing received by 50% for its 5-round duration. So, use blind to your advantage by pairing Call Darkness with the Crow's Nocturnal Strike. While it usually has a high chance to miss, Nocturnal Strike will always hit if the target is blind.
There are a few other abilities that benefit from a blind debuff, including the Ghostly Skull's Spectral Strike, Nordrassil Whisp's Light, and the Pandaren Monk's Fury of 1,000 Fists. Keep that synergy in mind when building a strong team! But remember: facing an Elemental opponent will render Call Darkness mostly useless for this combo, as they're immune to weather effects. Nonetheless, the Crow is a valuable asset in any battle pet collection!
If you don't spot any capturable Crows on Darkmoon Island, don't worry, you'll never see them around. And that's ok! The Crow only spawns as a secondary pet to Darkmoon Glowflies (above level 5) all around the island. If the Crow doesn't spawn as a backline pet initially, keep at it. A glowfly can also team up with a Sea Gull, Adder, Roach, or a Rat -- you may be on the island for a while if you're set on capturing a rare Crow.