Dread Wanderer

This creature enters tapped.
{2}{B}: Return this card from your graveyard to the battlefield. Activate only as a sorcery and only if you have one or fewer cards in hand.

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.

Skull Skaab

Exploit (When this creature enters, you may sacrifice a creature.)
Whenever a creature you control exploits a nontoken creature, create a 2/2 black Zombie creature token.

Diregraf Ghoul

Island

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.)

Headless Rider

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

Shambling Ghast

When this creature dies, choose one —
• Target creature an opponent controls gets -1/-1 until end of turn.
• Create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Swamp

Necroduality

Whenever a nontoken Zombie you control enters, create a token that's a copy of that creature.

Open the Graves

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