Flying

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)

When Bat Whisperer enters the battlefield, if an opponent lost life this turn, create a 1/1 black Bat creature token with flying.

Flying

{7}{B}, {T}, Sacrifice Blight Keeper: Target opponent loses 4 life and you gain 4 life.

Flying

{1}: Blighted Bat gains haste until end of turn.

Flying

When Bloodhunter Bat enters the battlefield, target player loses 2 life and you gain 2 life.

Flying

When Courier Bat enters the battlefield, if you gained life this turn, return up to one target creature card from your graveyard to your hand.

Flying

Bloodthirst 1 (If an opponent was dealt damage this turn, this creature enters the battlefield with a +1/+1 counter on it.)

Flying

Flying

When Eyetwitch dies, learn. (You may reveal a Lesson card you own from outside the game and put it into your hand, or discard a card to draw a card.)

Flying

{B}, Pay 1 life: Grimclaw Bats gets +1/+1 until end of turn.

Flying, first strike, haste

Flying, deathtouch

Whenever you gain life, Malakir Familiar gets +1/+1 until end of turn.

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)

Whenever a Human deals damage to you, destroy it.

Other non-Human creatures you control get +1/+1 and have undying. (When a creature with undying dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Flying

At the beginning of your upkeep, you may pay {2}{B}{B}. If you do, transform Screeching Bat.

At the beginning of your upkeep, you may pay {2}{B}{B}. If you do, transform Stalking Vampire.

Flying

{1}{B}, Exile Sengir Nosferatu: Create a 1/2 black Bat creature token with flying. It has "{1}{B}, Sacrifice this creature: Return an exiled card named Sengir Nosferatu to the battlefield under its owner's control."

Ward--Discard a card.

Whenever another nontoken Vampire you control dies, you may pay {1} and exile it. If you do, create a 1/1 black Bat creature token with flying. It gains "When this creature deals combat damage to a player, sacrifice it and return the exiled card to the battlefield tapped."

Flying (This creature can't be blocked except by creatures with flying or reach.)

{B}: Vampire Bats gets +1/+0 until end of turn. Activate no more than twice each turn.