Gray Merchant of Asphodel

When Gray Merchant of Asphodel 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.)

Putrid Goblin

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.)

Village Rites

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

Ghoulcaller's Chant

Choose one —
• Return target creature card from your graveyard to your hand.
• Return two target Zombie cards from your graveyard to your hand.

Crawl from the Cellar

Return target creature card from your graveyard to your hand. Put a +1/+1 counter on up to one target Zombie you control.
Flashback {3}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Accursed Marauder

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

Serrated Scorpion

When Serrated Scorpion dies, it deals 2 damage to each opponent and you gain 2 life.

Shambling Ghast

When Shambling Ghast 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 artifact: Add one mana of any color.")

Carrion Feeder

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

Foul-Tongue Shriek

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

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.

Lazotep Reaver

When Lazotep Reaver 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.)

Swamp

Shepherd of Rot

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

Troll of Khazad-dûm

Troll of Khazad-dûm can't be blocked except by three or more creatures.
Swampcycling {1} ({1}, Discard this card: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.)