Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

Corpse Connoisseur

When this creature enters, you may search your library for a creature card, put that card into your graveyard, then shuffle.
Unearth {3}{B} ({3}{B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Ghoulcaller Gisa

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

Fleshbag Marauder

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

Deadly Tempest

Destroy all creatures. Each player loses life equal to the number of creatures they controlled that were destroyed this way.

Crypt of Agadeem

This land enters tapped.
{T}: Add {B}.
{2}, {T}: Add {B} for each black creature card in your graveyard.

Cryptbreaker

{1}{B}, {T}, Discard a card: Create a 2/2 black Zombie creature token.
Tap three untapped Zombies you control: You draw a card and you lose 1 life.

Phyrexian Tower

{T}: Add {C}.
{T}, Sacrifice a creature: Add {B}{B}.

Ashnod's Altar

Haunted Dead

When this creature enters, create a 1/1 white Spirit creature token with flying.
{1}{B}, Discard two cards: Return this card from your graveyard to the battlefield tapped.

Gravecrawler

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

Defile

Target creature gets -1/-1 until end of turn for each Swamp you control.

Blood Bairn

Sacrifice another creature: This creature gets +2/+2 until end of turn.

Undead Warchief

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

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.)

Takenuma, Abandoned Mire

{T}: Add {B}.
Channel — {3}{B}, Discard this card: Mill three cards, then return a creature or planeswalker card from your graveyard to your hand. This ability costs {1} less to activate for each legendary creature you control.

Three Tree City

As Three Tree City enters, choose a creature type.
{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to the number of creatures you control of the chosen type.

Withering Torment

Destroy target creature or enchantment. You lose 2 life.

Lazotep Reaver

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.)

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.

Lotleth Giant

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

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Killing Wave

For each creature, its controller sacrifices it unless they pay X life.

Accursed Marauder

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

Headless Rider

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

Crypt Ghast

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
Whenever you tap a Swamp for mana, add an additional {B}.

Silumgar Scavenger

Flying
Exploit (When this creature enters, you may sacrifice a creature.)
Whenever another creature you control dies, put a +1/+1 counter on this creature. It gains haste until end of turn if it exploited that creature.

Persistent Constrictor

At the beginning of each opponent's upkeep, they lose 1 life and you put a -1/-1 counter on up to one target creature they control.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Dark Ritual

Shambling Ghast

When this creature dies, choose one —
• Target creature an opponent controls gets -1/-1 until end of turn.
• Create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Archghoul of Thraben

Whenever this creature or another Zombie you control dies, look at the top card of your library. If it's a Zombie card, you may reveal it and put it into your hand. If you don't put the card into your hand, you may put it into your graveyard.

Go for the Throat

Cemetery Reaper

Other Zombie creatures you control get +1/+1.
{2}{B}, {T}: Exile target creature card from a graveyard. Create a 2/2 black Zombie creature token.

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.

Foul-Tongue Shriek

Target opponent loses 1 life for each attacking creature you control. You gain that much life.

Lord of the Undead

Other Zombie creatures get +1/+1.
{1}{B}, {T}: Return target Zombie card from your graveyard to your hand.

Village Rites

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards.

Boneyard Desecrator

Menace
{1}{B}, Sacrifice another creature: Put a +1/+1 counter on this creature. If an outlaw was sacrificed this way, create a Treasure token. (Assassins, Mercenaries, Pirates, Rogues, and Warlocks are outlaws.)

Tragic Slip

Target creature gets -1/-1 until end of turn.
Morbid — That creature gets -13/-13 until end of turn instead if a creature died this turn.

Bojuka Bog

This land enters tapped.
When this land enters, exile target player's graveyard.
{T}: Add {B}.

Snow-Covered Swamp

War Room

{T}: Add {C}.
{3}, {T}, Pay life equal to the number of colors in your commanders' color identity: Draw a card.

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.)

Cabal Coffers

{2}, {T}: Add {B} for each Swamp you control.

Lord of the Accursed

Other Zombies you control get +1/+1.
{1}{B}, {T}: All Zombies gain menace until end of turn.

Maalfeld Twins

When this creature dies, create two 2/2 black Zombie creature tokens.

Sol Ring

Ayara, First of Locthwain

Whenever Ayara or another black creature you control enters, each opponent loses 1 life and you gain 1 life.
{T}, Sacrifice another black creature: Draw a card.

Gisa, the Hellraiser

Ward—{2}, Pay 2 life.
Skeletons and Zombies you control get +1/+1 and have menace.
Whenever you commit a crime, create two tapped 2/2 blue and black Zombie Rogue creature tokens. This ability triggers only once each turn. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime.)

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Bellowing Mauler

At the beginning of your end step, each player loses 4 life unless they sacrifice a nontoken creature of their choice.

Nykthos, Shrine to Nyx

{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

Zul Ashur, Lich Lord

Ward—Pay 2 life. (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays 2 life.)
{T}: You may cast target Zombie creature card from your graveyard this turn.

Acererak the Archlich

When Acererak enters, if you haven't completed Tomb of Annihilation, return Acererak to its owner's hand and venture into the dungeon.
Whenever Acererak attacks, for each opponent, you create a 2/2 black Zombie creature token unless that player sacrifices a creature of their choice.

Jet Medallion

Black spells you cast cost {1} less to cast.

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.

Herald of the Dreadhorde

When this creature dies, amass Zombies 2. (Put two +1/+1 counters 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.)

Urza's Saga

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — This Saga gains "{T}: Add {C}."
II — This Saga gains "{2}, {T}: Create a 0/0 colorless Construct artifact creature token with 'This token gets +1/+1 for each artifact you control.'"
III — Search your library for an artifact card with mana cost {0} or {1}, put it onto the battlefield, then shuffle.

Diregraf Horde

When this creature enters, create two 2/2 black Zombie creature tokens with decayed. When you do, exile up to two target cards from graveyards. (A creature with decayed can't block. When it attacks, sacrifice it at end of combat.)

Blasting Station

{T}, Sacrifice a creature: This artifact deals 1 damage to any target.
Whenever a creature enters, you may untap this artifact.

Thran Vigil

Whenever one or more artifact and/or creature cards leave your graveyard during your turn, put a +1/+1 counter on target creature you control.

Geralf's Messenger

This creature enters tapped.
When this creature enters, target opponent loses 2 life.
Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Champion of the Perished

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

Patchwork Banner

As this artifact enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
{T}: Add one mana of any color.

Priest of Forgotten Gods

{T}, Sacrifice two other creatures: Any number of target players each lose 2 life and sacrifice a creature of their choice. You add {B}{B} and draw a card.

Apprentice Necromancer

{B}, {T}, Sacrifice this creature: Return target creature card from your graveyard to the battlefield. That creature gains haste. At the beginning of the next end step, sacrifice it.

Rotting Regisaur

At the beginning of your upkeep, discard a card.

Polluted Dead

When this creature dies, destroy target land.

Calculating Lich

Menace
Whenever a creature attacks one of your opponents, that player loses 1 life.

Vogar, Necropolis Tyrant

Menace
Whenever another creature dies during your turn, put a +1/+1 counter on Vogar.
When Vogar dies, draw a card for each +1/+1 counter on it.

Altar of Dementia

Sacrifice a creature: Target player mills cards equal to the sacrificed creature's power.

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.)

Liliana, Dreadhorde General

Whenever a creature you control dies, draw a card.
+1: Create a 2/2 black Zombie creature token.
−4: Each player sacrifices two creatures of their choice.
−9: Each opponent chooses a permanent they control of each permanent type and sacrifices the rest.

Blood Artist

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

Vindictive Lich

When this creature dies, choose one or more. Each mode must target a different player.
• Target opponent sacrifices a creature of their choice.
• Target opponent discards two cards.
• Target opponent loses 5 life.

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.")

Carrion Feeder

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

Infectious Host

When this creature dies, target player loses 2 life.

Cabal Stronghold

{T}: Add {C}.
{3}, {T}: Add {B} for each basic Swamp you control.

Ammit Eternal

Afflict 3 (Whenever this creature becomes blocked, defending player loses 3 life.)
Whenever an opponent casts a spell, put a -1/-1 counter on this creature.
Whenever this creature deals combat damage to a player, remove all -1/-1 counters from it.

Infernal Grasp

Destroy target creature. You lose 2 life.

Lash of the Balrog

As an additional cost to cast this spell, sacrifice a creature or pay {4}.
Destroy target creature.

Unstoppable Slasher

Deathtouch
Whenever this creature deals combat damage to a player, they lose half their life, rounded up.
When this creature dies, if it had no counters on it, return it to the battlefield tapped under its owner's control with two stun counters on it.