Devouring Swarm

Flying
Sacrifice a creature: This creature gets +1/+1 until end of turn.

Diabolic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Return target creature card from your graveyard to your hand.

Target player reveals their hand. You choose a nonland card from it. That player discards that card.

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

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

Deathtouch
Whenever this creature enters or attacks, create two 2/2 black Zombie creature tokens.

When this creature enters, you may return target creature card from your graveyard to your hand.