Accursed Marauder

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

Nested Shambler

When Nested Shambler dies, create X tapped 1/1 green Squirrel creature tokens, where X is Nested Shambler's power.

Grim Servant

Menace
When Grim Servant enters, search your library for a card with mana value less than or equal to your devotion to black, reveal it, put it into your hand, then shuffle. You lose 3 life. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Vile Entomber

Deathtouch
When Vile Entomber enters, search your library for a card, put that card into your graveyard, then shuffle.

Unstoppable Slasher

Deathtouch
Whenever Unstoppable Slasher deals combat damage to a player, they lose half their life, rounded up.
When Unstoppable Slasher 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.

Maalfeld Twins

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

Death Baron

Skeletons you control and other Zombies you control get +1/+1 and have deathtouch.

Hungry Ghoul

{1}, Sacrifice another creature: Put a +1/+1 counter on this creature.

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.

Stitcher's Supplier

When Stitcher's Supplier enters or dies, mill three cards. (Put the top three cards of your library into your graveyard.)

Warren Soultrader

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

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.)

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.)

Soul-Shackled Zombie

When this creature enters, exile up to two target cards from a single graveyard. If at least one creature card was exiled this way, each opponent loses 2 life and you gain 2 life.