Rotten Reunion

Exile up to one target card from a graveyard. Create a 2/2 black Zombie creature token with decayed. (It can't block. When it attacks, sacrifice it at end of combat.)
Flashback {1}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Ghoulish Procession

Whenever one or more nontoken creatures die, create a 2/2 black Zombie creature token with decayed. This ability triggers only once each turn. (A creature with decayed can't block. When it attacks, sacrifice it at end of combat.)

Grim Physician

When this creature dies, target creature an opponent controls gets -1/-1 until end of turn.

Blood Pact

Target player draws two cards and loses 2 life.

Defenestrate

Headless Rider

Whenever this creature or another nontoken Zombie you control dies, create a 2/2 black Zombie creature token.

Lotleth Giant

Undergrowth — When this creature enters, it deals 1 damage to target opponent for each creature card in your graveyard.

Rot-Tide Gargantua

Exploit (When this creature enters, you may sacrifice a creature.)
When this creature exploits a creature, each opponent sacrifices a creature of their choice.

Gravedigger

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

Unhallowed Phalanx

Necrosynthesis

Enchant creature
Enchanted creature has "Whenever another creature dies, put a +1/+1 counter on this creature."
When enchanted creature dies, look at the top X cards of your library, where X is its power. Put one of those cards into your hand and the rest on the bottom of your library in a random order.

Bladebrand

Target creature gains deathtouch until end of turn.
Draw a card.

Swamp

Undead Servant

When this creature enters, create a 2/2 black Zombie creature token for each card named Undead Servant in your graveyard.

Hobbling Zombie

Deathtouch
When this creature dies, create a 2/2 black Zombie creature token with decayed. (It can't block. When it attacks, sacrifice it at end of combat.)

No Way Out

Target opponent discards two cards. You create a 2/2 black Zombie creature token with decayed. (It can't block. When it attacks, sacrifice it at end of combat.)

Diregraf Ghoul

Duress

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

Fleshbag Marauder

When this creature enters, each player sacrifices a creature of their choice.

Necrotic Hex

Each player sacrifices six creatures of their choice. You create six tapped 2/2 black Zombie creature tokens.

Liliana's Steward

{T}, Sacrifice this creature: Target opponent discards a card. Activate only as a sorcery.

Siege Zombie

Tap three untapped creatures you control: Each opponent loses 1 life.

Undying Malice

Until end of turn, target creature gains "When this creature dies, return it to the battlefield tapped under its owner's control with a +1/+1 counter on it."

Walking Corpse

Crawl from the Cellar

Return target creature card from your graveyard to your hand. Put a +1/+1 counter on up to one target Zombie you control.
Flashback {3}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Bone Splinters

As an additional cost to cast this spell, sacrifice a creature.
Destroy target creature.