Undead Warchief

Zombie spells you cast cost {1} less to cast.
Zombie creatures you control get +2/+1.

Fleshbag Marauder

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

Infectious Horror

Whenever Infectious Horror attacks, each opponent loses 2 life.

Bad Moon

Death Baron

Skeletons you control and other Zombies you control get +1/+1 and have deathtouch. (Any amount of damage they deal to a creature is enough to destroy it.)

Cackling Fiend

When Cackling Fiend enters, each opponent discards a card.

Delirium Skeins

Nested Ghoul

Whenever a source deals damage to Nested Ghoul, create a 2/2 black Phyrexian Zombie creature token.

Grave Titan

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

Skulking Knight

Flanking (Whenever a creature without flanking blocks this creature, the blocking creature gets -1/-1 until end of turn.)
When Skulking Knight becomes the target of a spell or ability, sacrifice it.

Endless Ranks of the Dead

At the beginning of your upkeep, create X 2/2 black Zombie creature tokens, where X is half the number of Zombies you control, rounded down.

Severed Legion

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)

Rotting Fensnake

Carrion Wurm

Whenever Carrion Wurm attacks or blocks, any player may exile three cards from their graveyard. If a player does, Carrion Wurm assigns no combat damage this turn.

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.)

Maggot Carrier

When Maggot Carrier enters, each player loses 1 life.

Damnation

Destroy all creatures. They can't be regenerated.

Soulless One

Soulless One's power and toughness are each equal to the number of Zombies on the battlefield plus the number of Zombie cards in all graveyards.

Yixlid Jailer

Walking Corpse

Plague Wind

Destroy all creatures you don't control. They can't be regenerated.

Call to the Grave

At the beginning of each player's upkeep, that player sacrifices a non-Zombie creature of their choice.
At the beginning of the end step, if no creatures are on the battlefield, sacrifice Call to the Grave.

Blind Creeper

Whenever a player casts a spell, Blind Creeper gets -1/-1 until end of turn.

Unbreathing Horde

Unbreathing Horde enters with a +1/+1 counter on it for each other Zombie you control and each Zombie card in your graveyard.
If Unbreathing Horde would be dealt damage, prevent that damage and remove a +1/+1 counter from it.

Forsaken Wastes

Players can't gain life.
At the beginning of each player's upkeep, that player loses 1 life.
Whenever Forsaken Wastes becomes the target of a spell, that spell's controller loses 5 life.