Gisa and Geralf

When Gisa and Geralf enters, mill four cards.
Once during each of your turns, you may cast a Zombie creature spell from your graveyard.

Death Baron

Skeletons you control and other Zombies you control get +1/+1 and have deathtouch. (Any amount of damage they deal to a creature is enough to destroy it.)

Liliana's Mastery

Zombies you control get +1/+1.
When this enchantment enters, create two 2/2 black Zombie creature tokens.

Essence Scatter

Wight

This creature enters tapped.
Life Drain — Whenever a creature dealt damage by this creature this turn dies, create a tapped 2/2 black Zombie creature token and exile that card.

Diregraf Colossus

This creature enters with a +1/+1 counter on it for each Zombie card in your graveyard.
Whenever you cast a Zombie spell, create a tapped 2/2 black Zombie creature token.

Tainted Adversary

Deathtouch
When this creature enters, you may pay {2}{B} any number of times. When you pay this cost one or more times, put that many +1/+1 counters on this creature, then create twice that many 2/2 black Zombie creature tokens with decayed. (A creature with decayed can't block. When it attacks, sacrifice it at end of combat.)

Dismal Backwater

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {U} or {B}.

Swamp

Festerleech

Whenever this creature deals combat damage to a player, you mill two cards.
{1}{B}: This creature gets +2/+2 until end of turn. Activate only once each turn.

Endless Ranks of the Dead

At the beginning of your upkeep, create X 2/2 black Zombie creature tokens, where X is half the number of Zombies you control, rounded down.

Island

Larder Zombie

Defender
Tap three untapped creatures you control: Surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)

Lord of the Accursed

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