Swamp

Typhoid Rats

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Harvester of Souls

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Whenever another nontoken creature dies, you may draw a card.

Have

Moan of the Unhallowed

Create two 2/2 black Zombie creature tokens.
Flashback {5}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Ozox, the Clattering King

Ozox, the Clattering King can't block.
When Ozox dies, create Jumblebones, a legendary 2/1 black Skeleton creature token with "This creature can't block" and "When this creature leaves the battlefield, return target card named Ozox, the Clattering King from your graveyard to your hand."

Thriving Moor

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

Doomed Dissenter

When Doomed Dissenter dies, create a 2/2 black Zombie creature token.

Murder

Deadly Dispute

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Morbid Opportunist

Whenever one or more other creatures die, draw a card. This ability triggers only once each turn.

Wriggling Grub

When Wriggling Grub dies, create two 1/1 black and green Worm creature tokens.

Tragic Slip

Target creature gets -1/-1 until end of turn.
Morbid — That creature gets -13/-13 until end of turn instead if a creature died this turn.

Ghastly

Reaper from the Abyss

Flying
Morbid — At the beginning of each end step, if a creature died this turn, destroy target non-Demon creature.

Army of the Damned

Create thirteen tapped 2/2 black Zombie creature tokens.
Flashback {7}{B}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)