Swamp

Bone Splinters

As an additional cost to cast this spell, sacrifice a creature.
Destroy target creature.

When Tattered Mummy dies, each opponent loses 2 life.

Zombies you control get +1/+1.
When Liliana's Mastery enters, create two 2/2 black Zombie creature tokens.

When Filigree Familiar enters, you gain 2 life.
When Filigree Familiar dies, draw a card.

Whenever Infectious Horror attacks, each opponent loses 2 life.

Other Zombies you control get +1/+1.
{1}{B}, {T}: All Zombies gain menace until end of turn.

When Gravedigger enters, you may return target creature card from your graveyard to your hand.

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

Whenever Zulaport Cutthroat or another creature you control dies, each opponent loses 1 life and you gain 1 life.

{1}{B}: Return Reassembling Skeleton from your graveyard to the battlefield tapped.

As an additional cost to cast this spell, sacrifice a creature.
Draw three cards.

Destroy target non-Zombie creature. It can't be regenerated. Return up to one target Zombie card from your graveyard to your hand.

Menace
When Rot Hulk enters, return up to X target Zombie cards from your graveyard to the battlefield, where X is the number of opponents you have.

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

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

Each opponent loses 1 life for each creature you control.

{2}{B}, Exile a creature card from your graveyard: Create a tapped 2/2 black Zombie creature token.

Whenever a nontoken creature you control dies, create a 2/2 black Zombie creature token.

All creatures get -4/-4 until end of turn.

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