Contamination

At the beginning of your upkeep, sacrifice Contamination unless you sacrifice a creature.
If a land is tapped for mana, it produces {B} instead of any other type and amount.

Lord of the Undead

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

Unholy Grotto

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

Dark Ritual

Sarcomancy

When Sarcomancy enters the battlefield, create a 2/2 black Zombie creature token.
At the beginning of your upkeep, if there are no Zombies on the battlefield, Sarcomancy deals 1 damage to you.

Undead Warchief

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

Grave Defiler

When Grave Defiler enters the battlefield, reveal the top four cards of your library. Put all Zombie cards revealed this way into your hand and the rest on the bottom of your library in any order.
{1}{B}: Regenerate Grave Defiler.

Crystal Vein

{T}: Add {C}.
{T}, Sacrifice Crystal Vein: Add {C}{C}.

Carnophage

At the beginning of your upkeep, tap Carnophage unless you pay 1 life.

Corrupt

Corrupt deals damage to any target equal to the number of Swamps you control. You gain life equal to the damage dealt this way.

Gempalm Polluter

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

Swamp

Carrion Feeder

Carrion Feeder can't block.
Sacrifice a creature: Put a +1/+1 counter on Carrion Feeder.

Cabal Coffers

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

Shepherd of Rot

{T}: Each player loses 1 life for each Zombie on the battlefield.

Duress

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