Have

Zombie Trailblazer

Tap an untapped Zombie you control: Target land becomes a Swamp until end of turn.
Tap an untapped Zombie you control: Target creature gains swampwalk until end of turn. (It can't be blocked as long as defending player controls a Swamp.)

Ghoulcaller Gisa

{B}, {T}, Sacrifice another creature: Create X 2/2 black Zombie creature tokens, where X is the sacrificed creature's power.

Army of the Damned

Create thirteen tapped 2/2 black Zombie creature tokens.
Flashback {7}{B}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Counterspell

Proxy

Gravecrawler

This creature can't block.
You may cast this card from your graveyard as long as you control a Zombie.

Gleaming Overseer

When this creature enters, amass Zombies 1. (Put a +1/+1 counter on an Army you control. It's also a Zombie. If you don't control an Army, create a 0/0 black Zombie Army creature token first.)
Zombie tokens you control have hexproof and menace.

Necrotic Hex

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

Don't Have

Graveborn Muse

At the beginning of your upkeep, you draw X cards and you lose X life, where X is the number of Zombies you control.

Hordewing Skaab

Flying
Other Zombies you control have flying.
Whenever one or more Zombies you control deal combat damage to one or more of your opponents, you may draw cards equal to the number of opponents dealt damage this way. If you do, discard that many cards.

Bad Moon

Liliana, the Last Hope

+1: Up to one target creature gets -2/-1 until your next turn.
−2: Mill two cards, then you may return a creature card from your graveyard to your hand.
−7: You get an emblem with "At the beginning of your end step, create X 2/2 black Zombie creature tokens, where X is two plus the number of Zombies you control."

Braids, Arisen Nightmare

At the beginning of your end step, you may sacrifice an artifact, creature, enchantment, land, or planeswalker. If you do, each opponent may sacrifice a permanent of their choice that shares a card type with it. For each opponent who doesn't, that player loses 2 life and you draw a card.

Grave Titan

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

Getting

Vizier of the Scorpion

When this creature enters, amass Zombies 1. (Put a +1/+1 counter on an Army you control. It's also a Zombie. If you don't control an Army, create a 0/0 black Zombie Army creature token first.)
Zombie tokens you control have deathtouch.

Gisa and Geralf

When Gisa and Geralf enters, mill four cards.
Once during each of your turns, you may cast a Zombie creature spell from your graveyard.

Noosegraf Mob

This creature enters with five +1/+1 counters on it.
Whenever a player casts a spell, remove a +1/+1 counter from this creature. If you do, create a 2/2 black Zombie creature token.

Go for the Throat

Wilhelt, the Rotcleaver

Whenever another Zombie you control dies, if it didn't have decayed, create a 2/2 black Zombie creature token with decayed. (It can't block. When it attacks, sacrifice it at end of combat.)
At the beginning of your end step, you may sacrifice a Zombie. If you do, draw a card.

Nim Deathmantle

Equipped creature gets +2/+2, has intimidate, and is a black Zombie. (A creature with intimidate can't be blocked except by artifact creatures and/or creatures that share a color with it.)
Whenever a nontoken creature is put into your graveyard from the battlefield, you may pay {4}. If you do, return that card to the battlefield and attach this Equipment to it.
Equip {4}

Gravespawn Sovereign

Tap five untapped Zombies you control: Put target creature card from a graveyard onto the battlefield under your control.

Agent of the Iron Throne

Commander creatures you own have "Whenever an artifact or creature you control is put into a graveyard from the battlefield, each opponent loses 1 life."

Ghouls' Night Out

For each player, choose a creature card in that player's graveyard. Put those cards onto the battlefield under your control. They're black Zombies in addition to their other colors and types and they gain decayed. (A creature with decayed can't block. When it attacks, sacrifice it at end of combat.)

An Offer You Can't Refuse

Counter target noncreature spell. Its controller creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Demonic Tutor

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

Plague Belcher

Menace
When this creature enters, put two -1/-1 counters on target creature you control.
Whenever another Zombie you control dies, each opponent loses 1 life.

Blood Artist

Whenever this creature or another creature dies, target player loses 1 life and you gain 1 life.

Poppet Factory

Creature tokens you control lose all abilities and have base power and toughness 3/3.
At the beginning of your upkeep, you may transform this artifact.

Poppet Stitcher

Whenever you cast an instant or sorcery spell, create a 2/2 black Zombie creature token with decayed. (It can't block. When it attacks, sacrifice it at end of combat.)
At the beginning of your upkeep, if you control three or more creature tokens, you may transform this creature.

Poppet Stitcher // Poppet Factory

Snuff Out

If you control a Swamp, you may pay 4 life rather than pay this spell's mana cost.
Destroy target nonblack creature. It can't be regenerated.

Scheming Symmetry

Choose two target players. Each of them searches their library for a card, then shuffles and puts that card on top.

Rise of the Dread Marn

Create X 2/2 black Zombie Berserker creature tokens, where X is the number of nontoken creatures that died this turn.
Foretell {B} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Death Pits of Rath

Whenever a creature is dealt damage, destroy it. It can't be regenerated.

Geralf, Visionary Stitcher

Zombies you control have flying.
{U}, {T}, Sacrifice another nontoken creature: Create an X/X blue Zombie creature token, where X is the sacrificed creature's toughness.

Bastion of Remembrance

When this enchantment enters, create a 1/1 white Human Soldier creature token.
Whenever a creature you control dies, each opponent loses 1 life and you gain 1 life.

Carrion Feeder

This creature can't block.
Sacrifice a creature: Put a +1/+1 counter on this creature.