Eyetwitch

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.)

Bloodhunter Bat

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

Bartizan Bats

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

Blight Keeper

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

Kelinore Bat

Courier Bat

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

Blind Hunter

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

Mirkwood Bats

Flying
Whenever you create or sacrifice a token, each opponent loses 1 life.

Duskhunter Bat

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

Ruin-Lurker Bat

Flying, lifelink
At the beginning of your end step, if you descended this turn, scry 1. (You descended if a permanent card was put into your graveyard from anywhere.)

Temple of the Dead

(Transforms from Aclazotz, Deepest Betrayal.)
{T}: Add {B}.
{2}{B}, {T}: Transform Temple of the Dead. Activate only if a player has one or fewer cards in hand and only as a sorcery.

Aclazotz, Deepest Betrayal

Flying, lifelink
Whenever Aclazotz attacks, each opponent discards a card. For each opponent who can't, you draw a card.
Whenever an opponent discards a land card, create a 1/1 black Bat creature token with flying.
When Aclazotz dies, return it to the battlefield tapped and transformed under its owner's control.

Aclazotz, Deepest Betrayal // Temple of the Dead

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.)

Deep-Cavern Bat

Flying, lifelink
When Deep-Cavern Bat enters, look at target opponent's hand. You may exile a nonland card from it until Deep-Cavern Bat leaves the battlefield.