Voracious Vermin

When Voracious Vermin enters, create a 1/1 black Rat creature token with "This creature can't block."
Whenever another creature you control dies, put a +1/+1 counter on Voracious Vermin.

Faceless Butcher

When Faceless Butcher enters, exile another target creature.
When Faceless Butcher leaves the battlefield, return the exiled card to the battlefield under its owner's control.

Pit Keeper

When Pit Keeper enters, if you have four or more creature cards in your graveyard, you may return target creature card from your graveyard to your hand.

Slum Reaper

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

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.)

Bubbling Muck

Until end of turn, whenever a player taps a Swamp for mana, that player adds an additional {B}.

Demon's Disciple

When Demon's Disciple enters, each player sacrifices a creature or planeswalker of their choice.

Crypt Rats

{X}: Crypt Rats deals X damage to each creature and each player. Spend only black mana on X.

Phyrexian Rager

When Phyrexian Rager enters, you draw a card and you lose 1 life.

Diregraf Horde

When Diregraf Horde 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.)

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.)

Dread Drone

When Dread Drone enters, create two 0/1 colorless Eldrazi Spawn creature tokens. They have "Sacrifice this creature: Add {C}."

Thorn of the Black Rose

Deathtouch
When Thorn of the Black Rose enters, you become the monarch.

Charcoal Diamond

Charcoal Diamond enters tapped.
{T}: Add {B}.

Skull Collector

At the beginning of your upkeep, return a black creature you control to its owner's hand.
{1}{B}: Regenerate Skull Collector.

Blight-Breath Catoblepas

When Blight-Breath Catoblepas enters, target creature an opponent controls gets -X/-X until end of turn, where X is your devotion to black. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Fleshbag Marauder

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

Dusk Legion Zealot

When Dusk Legion Zealot enters, you draw a card and you lose 1 life.

Cuombajj Witches

{T}: Cuombajj Witches deals 1 damage to any target and 1 damage to any target of an opponent's choice.