Vengeful Warchief

Whenever you lose life for the first time each turn, put a +1/+1 counter on this creature. (Damage causes loss of life.)

Shepherd of Rot

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

Wretched Anurid

Whenever another creature enters, you lose 1 life.

Fell Stinger

Deathtouch
Exploit (When this creature enters, you may sacrifice a creature.)
When this creature exploits a creature, target player draws two cards and loses 2 life.

Bake into a Pie

Destroy target creature. Create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")

Thriving Moor

This land enters tapped. As it enters, choose a color other than black.
{T}: Add {B} or one mana of the chosen color.

Carnophage

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

Swamp

Dreadhorde Invasion

At the beginning of your upkeep, you lose 1 life and 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.)
Whenever a Zombie token you control with power 6 or greater attacks, it gains lifelink until end of turn.

Plague Belcher

Menace
When this creature enters, put two -1/-1 counters on target creature you control.
Whenever another Zombie you control dies, each opponent loses 1 life.

Sangrophage

At the beginning of your upkeep, tap this creature unless you pay 2 life.

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.)

Greed

Nim Abomination

At the beginning of your end step, if this creature is untapped, you lose 3 life.