Swamp

Ossuary Rats

When this creature enters, it deals X damage to target creature or planeswalker an opponent controls, where X is the number of creature cards in your graveyard.

Moodmark Painter

Undergrowth — When this creature enters, target creature gains menace and gets +X/+0 until end of turn, where X is the number of creature cards in your graveyard. (It can't be blocked except by two or more creatures.)

Suspicious Shambler

{4}{B}{B}, Exile this card from your graveyard: Create two 2/2 black Zombie creature tokens. Activate only as a sorcery.

Shadowborn Demon

Flying
When this creature enters, destroy target non-Demon creature.
At the beginning of your upkeep, if there are fewer than six creature cards in your graveyard, sacrifice a creature.

Liliana's Elite

This creature gets +1/+1 for each creature card in your graveyard.

Stitcher's Supplier

When this creature enters or dies, mill three cards. (Put the top three cards of your library into your graveyard.)

Corpse Churn

Mill three cards, then you may return a creature card from your graveyard to your hand. (To mill three cards, put the top three cards of your library into your graveyard.)

Gorging Vulture

Flying
When this creature enters, mill four cards. You gain 1 life for each creature card milled this way. (To mill four cards, put the top four cards of your library into your graveyard.)

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.

Ghoul's Feast

Target creature gets +X/+0 until end of turn, where X is the number of creature cards in your graveyard.

Necrotic Wound

Undergrowth — Target creature gets -X/-X until end of turn, where X is the number of creature cards in your graveyard. If that creature would die this turn, exile it instead.

Graveblade Marauder

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Whenever this creature deals combat damage to a player, that player loses life equal to the number of creature cards in your graveyard.

Wailing Ghoul

When this creature enters, mill two cards. (Put the top two cards of your library into your graveyard.)