Diregraf Captain

Deathtouch
Other Zombie creatures you control get +1/+1.
Whenever another Zombie you control dies, target opponent loses 1 life.

Lord of the Accursed

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

Necroduality

Whenever a nontoken Zombie enters the battlefield under your control, create a token that's a copy of that creature.

Cleaver Skaab

{3}, {T}, Sacrifice another Zombie: Create two tokens that are copies of the sacrificed creature.

The Scarab God

At the beginning of your upkeep, each opponent loses X life and you scry X, where X is the number of Zombies you control.
{2}{U}{B}: Exile target creature card from a graveyard. Create a token that's a copy of it, except it's a 4/4 black Zombie.
When The Scarab God dies, return it to its owner's hand at the beginning of the next end step.

Death Baron

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

Diregraf Colossus

Diregraf Colossus enters the battlefield 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.

Gravecrawler

Gravecrawler can't block.
You may cast Gravecrawler from your graveyard as long as you control a Zombie.

Rooftop Storm

You may pay {0} rather than pay the mana cost for Zombie creature spells you cast.