Crows

 are NPC's available during the Dark Magic 2016 Event.

They serve as the usual roaming characters that must be collected by tapping. They spawn in groups of 8 every 3 hours.

Rewards
When tapped they give Magic.

Trivia

 * Dark Ravens also appeared during the Clean Sweep 2016 Event and Clean Sweep (2) 2016 Event due to a glitch in some games.