Spawnsire of Ulamog

Annihilator 1 (Whenever this creature attacks, defending player sacrifices a permanent.)
{4}: Create two 0/1 colorless Eldrazi Spawn creature tokens. They have "Sacrifice this creature: Add {C}."
{20}: Cast any number of Eldrazi spells from among cards you own outside the game without paying their mana costs.

Spawnbed Protector

At the beginning of your end step, return up to one target Eldrazi creature card from your graveyard to your hand. Create two 1/1 colorless Eldrazi Scion creature tokens with "Sacrifice this creature: Add {C}."

Ajani, Adversary of Tyrants

+1: Put a +1/+1 counter on each of up to two target creatures.
−2: Return target creature card with mana value 2 or less from your graveyard to the battlefield.
−7: You get an emblem with "At the beginning of your end step, create three 1/1 white Cat creature tokens with lifelink."

Gravebane Zombie

If Gravebane Zombie would die, put Gravebane Zombie on top of its owner's library instead.

Gravedig

Choose one —
• Target player creates a 2/2 black Zombie creature token.
• Return target creature card from your graveyard to your hand.
Entwine {2} (Choose both if you pay the entwine cost.)

Sigarda's Summons

Creatures you control with +1/+1 counters on them have base power and toughness 4/4, have flying, and are Angels in addition to their other types.

Zombie Mob

Zombie Mob enters with a +1/+1 counter on it for each creature card in your graveyard.
When Zombie Mob enters, exile all creature cards from your graveyard.

Lord of the Undead

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

Gravedigger

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

Zombie Infestation

Discard two cards: Create a 2/2 black Zombie creature token.

Ajani, Inspiring Leader

+2: You gain 2 life. Put two +1/+1 counters on up to one target creature.
−3: Exile target creature. Its controller gains 2 life.
−10: Creatures you control gain flying and double strike until end of turn.

Spawning Bed

{T}: Add {C}.
{6}, {T}, Sacrifice Spawning Bed: Create three 1/1 colorless Eldrazi Scion creature tokens. They have "Sacrifice this creature: Add {C}."

Zombie Apocalypse

Return all Zombie creature cards from your graveyard to the battlefield tapped, then destroy all Humans.

Pharika's Spawn

Escape—{5}{B}, Exile three other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)
Pharika's Spawn escapes with two +1/+1 counters on it. When it enters this way, each opponent sacrifices a non-Gorgon creature.

Graven Abomination

Whenever Graven Abomination attacks, exile target card from defending player's graveyard.

Mournful Zombie

Hobbling Zombie

Deathtouch
When Hobbling Zombie dies, create a 2/2 black Zombie creature token with decayed. (It can't block. When it attacks, sacrifice it at end of combat.)

Necromantic Summons

Put target creature card from a graveyard onto the battlefield under your control.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, that creature enters with two additional +1/+1 counters on it.

Zombie Master

Other Zombie creatures have swampwalk. (They can't be blocked as long as defending player controls a Swamp.)
Other Zombies have "{B}: Regenerate this permanent."

Undead Gladiator

{1}{B}, Discard a card: Return Undead Gladiator from your graveyard to your hand. Activate only during your upkeep.
Cycling {1}{B} ({1}{B}, Discard this card: Draw a card.)

Spawning Pool

Spawning Pool enters tapped.
{T}: Add {B}.
{1}{B}: Spawning Pool becomes a 1/1 black Skeleton creature with "{B}: Regenerate this creature" until end of turn. It's still a land. (If it regenerates, the next time it would be destroyed this turn, it isn't. Instead tap it, remove all damage from it, and remove it from combat.)

Undead Warchief

Zombie spells you cast cost {1} less to cast.
Zombie creatures you control get +2/+1.

Curse of Shallow Graves

Enchant player
Whenever a player attacks enchanted player with one or more creatures, that attacking player may create a tapped 2/2 black Zombie creature token.