Mikaeus, the Unhallowed

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
Whenever a Human deals damage to you, destroy it.
Other non-Human creatures you control get +1/+1 and have undying. (When a creature with undying dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Champion of the Perished

Whenever another Zombie you control enters, put a +1/+1 counter on this creature.

Lord of the Undead

Other Zombie creatures get +1/+1.
{1}{B}, {T}: Return target Zombie card from your graveyard to your hand.

Headless Rider

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

Necroduality

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

Accursed Marauder

When this creature enters, each player sacrifices a nontoken creature of their choice.

Rooftop Storm

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

Cleaver Skaab

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

Gravecrawler

This creature can't block.
You may cast this card from your graveyard as long as you control a Zombie.