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.

Cradle of the Accursed

{T}: Add {C}.
{3}, {T}, Sacrifice this land: Create a 2/2 black Zombie creature token. Activate only as a sorcery.

Corrupted Conviction

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

Writhing Necromass

This spell costs {1} less to cast for each creature card in your graveyard.
Deathtouch

Dread Return

Return target creature card from your graveyard to the battlefield.
Flashback—Sacrifice three creatures. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Lotleth Giant

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

Swamp

Vengeful Dead

Whenever this creature or another Zombie dies, each opponent loses 1 life.

Khenra Eternal

Afflict 1 (Whenever this creature becomes blocked, defending player loses 1 life.)

Blood Fountain

When this artifact enters, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.")
{3}{B}, {T}, Sacrifice this artifact: Return up to two target creature cards from your graveyard to your hand.

Accursed Marauder

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

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.)

Carrion Feeder

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