Bat

Bats are flying mammals (the only ones in the real world, in fact). Associated primarily with black mana, Magic 's bats tend to be fearsome and dangerous, a stark constrast to the harmless tiny insect-eating flyers from our world. More often than not they are associated with Vampires.

Wild oversized Bats that are native to all of ravnica, they aren't really agressive but can be provoked into attacking in swarms.

Sometimes they are used by the Orzhov Syndicate to scare and harass debtors that are overdue on their payment.

References: