Swamp

Diregraf Colossus

This creature enters with a +1/+1 counter on it for each Zombie card in your graveyard.
Whenever you cast a Zombie spell, create a tapped 2/2 black Zombie creature token.

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.)

Deadly Dispute

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Unholy Grotto

{T}: Add {C}.
{B}, {T}: Put target Zombie card from your graveyard on top of your library.

Cut Down

Destroy target creature with total power and toughness 5 or less.

Gray Merchant of Asphodel

When this creature enters, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Candy Grapple

Bargain (You may sacrifice an artifact, enchantment, or token as you cast this spell.)
Target creature gets -3/-3 until end of turn. If this spell was bargained, that creature gets -5/-5 until end of turn instead.

Undead Augur

Whenever this creature or another Zombie you control dies, you draw a card and you lose 1 life.

Dark Ritual

Gravecrawler

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

Cremate

Exile target card from a graveyard.
Draw a card.

Warren Soultrader

Pay 1 life, Sacrifice another creature: Create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Rotting Regisaur

At the beginning of your upkeep, discard a card.

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.

Postmortem Professor

This creature can't block.
Whenever this creature attacks, each opponent loses 1 life and you gain 1 life.
{1}{B}, Exile an instant or sorcery card from your graveyard: Return this card from your graveyard to the battlefield.

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.

Champion of the Perished

Whenever another Zombie you control enters, put a +1/+1 counter on this creature.

Carrion Feeder

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

Bad River

This land enters tapped.
{T}, Sacrifice this land: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Profane Insight

You draw a card and you lose 1 life. (Then exile this card. You may cast the creature later from exile.)

Foulmire Knight

Foulmire Knight // Profane Insight

Gempalm Polluter

Cycling {B}{B} ({B}{B}, Discard this card: Draw a card.)
When you cycle this card, you may have target player lose life equal to the number of Zombies on the battlefield.

Blood Artist

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

Shoot the Sheriff

Destroy target non-outlaw creature. (Assassins, Mercenaries, Pirates, Rogues, and Warlocks are outlaws. Everyone else is fair game.)

Headless Rider

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