Gurmag Swiftwing

Ghastly Gloomhunter

Kicker {3}{B} (You may pay an additional {3}{B} as you cast this spell.)
Flying, lifelink
If this creature was kicked, it enters with two +1/+1 counters on it.

Belfry Spirit

Flying
Haunt (When this creature dies, exile it haunting target creature.)
When this creature enters or the creature it haunts dies, create two 1/1 black Bat creature tokens with flying.

Skeletal Vampire

Flying
When this creature enters, create two 1/1 black Bat creature tokens with flying.
{3}{B}{B}, Sacrifice a Bat: Create two 1/1 black Bat creature tokens with flying.
Sacrifice a Bat: Regenerate this creature.

Desecrated Tomb

Whenever one or more creature cards leave your graveyard, create a 1/1 black Bat creature token with flying.

Sengir Bats

Flying
Whenever a creature dealt damage by this creature this turn dies, put a +1/+1 counter on this creature.

Regal Bloodlord

Flying
At the beginning of each end step, if you gained life this turn, create a 1/1 black Bat creature token with flying.

Eyetwitch

Flying
When this creature 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.)

Dementia Bat

Flying
{4}{B}, Sacrifice this creature: Target player discards two cards.

Grimclaw Bats

Flying
{B}, Pay 1 life: This creature gets +1/+1 until end of turn.

Bloodhunter Bat

Flying
When this creature enters, target player loses 2 life and you gain 2 life.

Malakir Familiar

Flying, deathtouch
Whenever you gain life, this creature gets +1/+1 until end of turn.

Dakmor Bat

Bat Whisperer

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

Scion of the Ur-Dragon

Flying
{2}: Search your library for a Dragon permanent card and put it into your graveyard. If you do, Scion of the Ur-Dragon becomes a copy of that card until end of turn. Then shuffle.

Bartizan Bats

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

Basilica Screecher

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.)

Stalking Vampire

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

Screeching Bat

Flying
At the beginning of your upkeep, you may pay {2}{B}{B}. If you do, transform this creature.

Screeching Bat // Stalking Vampire

Marrow Bats

Flying
Pay 4 life: Regenerate this creature.

Duskhunter Bat

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

Blight Keeper

Flying
{7}{B}, {T}, Sacrifice this creature: Target opponent loses 4 life and you gain 4 life.

Blighted Bat

Flying
{1}: This creature gains haste until end of turn.

Vampire Bats

Flying (This creature can't be blocked except by creatures with flying or reach.)
{B}: This creature gets +1/+0 until end of turn. Activate no more than twice each turn.

Kelinore Bat

Search for Blex

Look at the top five cards of your library. You may put any number of them into your hand and the rest into your graveyard. You lose 3 life for each card you put into your hand this way.

Blex, Vexing Pest

Other Pests, Bats, Insects, Snakes, and Spiders you control get +1/+1.
When Blex dies, you gain 4 life.

Blex, Vexing Pest // Search for Blex

Foundry Screecher

Flying
This creature gets +1/+0 as long as you control an artifact.

Gloomhunter

Blind Hunter

Flying
Haunt (When this creature dies, exile it haunting target creature.)
When this creature enters or the creature it haunts dies, target player loses 2 life and you gain 2 life.

Dirge Bat

Mutate {4}{B}{B} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Flash
Flying
Whenever this creature mutates, destroy target creature or planeswalker an opponent controls.

Sengir Nosferatu

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