Swamp

Mummy Paramount

Whenever another Zombie you control enters, Mummy Paramount gets +1/+1 until end of turn.

Pontiff of Blight

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
Other creatures you control have extort. (If a creature has multiple instances of extort, each triggers separately.)

Festering Mummy

When Festering Mummy dies, you may put a -1/-1 counter on target creature.

From Under the Floorboards

Madness {X}{B}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)
Create three tapped 2/2 black Zombie creature tokens and you gain 3 life. If this spell's madness cost was paid, instead create X of those tokens and you gain X life.

Unraveling Mummy

{1}{W}: Target attacking Zombie gains lifelink until end of turn.
{1}{B}: Target attacking Zombie gains deathtouch until end of turn.

Liliana's Mastery

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

Forsaken Sanctuary

Forsaken Sanctuary enters tapped.
{T}: Add {W} or {B}.

In Oketra's Name

Zombies you control get +2/+1 until end of turn. Other creatures you control get +1/+1 until end of turn.

Shamble Back

Exile target creature card from a graveyard. Create a 2/2 black Zombie creature token. You gain 2 life.

Ammit Eternal

Afflict 3 (Whenever this creature becomes blocked, defending player loses 3 life.)
Whenever an opponent casts a spell, put a -1/-1 counter on Ammit Eternal.
Whenever Ammit Eternal deals combat damage to a player, remove all -1/-1 counters from it.

Grixis Slavedriver

When Grixis Slavedriver leaves the battlefield, create a 2/2 black Zombie creature token.
Unearth {3}{B} ({3}{B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Josu Vess, Lich Knight

Kicker {5}{B} (You may pay an additional {5}{B} as you cast this spell.)
Menace
When Josu Vess, Lich Knight enters, if it was kicked, create eight 2/2 black Zombie Knight creature tokens with menace.

Unconventional Tactics

Target creature gets +3/+3 and gains flying until end of turn.
Whenever a Zombie you control enters, you may pay {W}. If you do, return Unconventional Tactics from your graveyard to your hand.

Time to Reflect

Exile target creature that blocked or was blocked by a Zombie this turn.

Thopter Arrest

When Thopter Arrest enters, exile target artifact or creature an opponent controls until Thopter Arrest leaves the battlefield.

Merciless Eternal

Afflict 2 (Whenever this creature becomes blocked, defending player loses 2 life.)
{2}{B}, Discard a card: Merciless Eternal gets +2/+2 until end of turn.

Gravedigger

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

Bontu's Monument

Black creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, each opponent loses 1 life and you gain 1 life.

Forlorn Pseudamma

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
Inspired — Whenever Forlorn Pseudamma becomes untapped, you may pay {2}{B}. If you do, create a 2/2 black Zombie enchantment creature token.

Plains

Graf Harvest

Zombies you control have menace. (They can't be blocked except by two or more creatures.)
{3}{B}, Exile a creature card from your graveyard: Create a 2/2 black Zombie creature token.

Black Oak of Odunos

Defender
{B}, Tap another untapped creature you control: Black Oak of Odunos gets +1/+1 until end of turn.

Lord of the Accursed

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

Teysa, Envoy of Ghosts

Vigilance, protection from creatures
Whenever a creature deals combat damage to you, destroy that creature. Create a 1/1 white and black Spirit creature token with flying.

Raiders' Wake

Whenever an opponent discards a card, that player loses 2 life.
Raid — At the beginning of your end step, if you attacked this turn, target opponent discards a card.

Stir the Sands

Create three 2/2 black Zombie creature tokens.
Cycling {3}{B} ({3}{B}, Discard this card: Draw a card.)
When you cycle Stir the Sands, create a 2/2 black Zombie creature token.