2 - essential non-creature

Dark Petition

Search your library for a card, put that card into your hand, then shuffle.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, add {B}{B}{B}.

1 - engine recovery

Bone Harvest

Put any number of target creature cards from your graveyard on top of your library.
Draw a card at the beginning of the next turn's upkeep.

0.1 - additional engine

Gnawing Zombie

{1}{B}, Sacrifice a creature: Target player loses 1 life and you gain 1 life.

3 - non-essential non-creature

Dredge

Sacrifice a creature or land.
Draw a card.

0 - engine

Diregraf Colossus

Diregraf Colossus 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.

Razaketh's Rite

Search your library for a card, put that card into your hand, then shuffle.
Cycling {B} ({B}, Discard this card: Draw a card.)

Death Stroke

4 - extra creatures

Diregraf Ghoul

Sewers of Estark

Choose target creature. If it's attacking, it can't be blocked this turn. If it's blocking, prevent all combat damage that would be dealt this combat by it and each creature it's blocking.

Death Denied

Return X target creature cards from your graveyard to your hand.

Doom Blade

Bone Splinters

As an additional cost to cast this spell, sacrifice a creature.
Destroy target creature.

Demonic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Diabolic Tutor

Mind Knives

Target opponent discards a card at random.

Corrupted Conviction

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards.

Cerebral Confiscation

Choose one —
• Target opponent discards two cards.
• Target opponent reveals their hand. You choose a nonland card from it. That player discards that card.

Agency Coroner

{2}{B}, Sacrifice another creature: Draw a card. If the sacrificed creature was suspected, draw two cards instead.

Altar's Reap

Dark Inquiry

Target opponent reveals their hand. You choose a nonland card from it. That player discards that card.

Coercion

Target opponent reveals their hand. You choose a card from it. That player discards that card.

Lay Bare the Heart

Target opponent reveals their hand. You choose a nonlegendary, nonland card from it. That player discards that card.

Hungry Ghoul

{1}, Sacrifice another creature: Put a +1/+1 counter on this creature.

Reassembling Skeleton

{1}{B}: Return this card from your graveyard to the battlefield tapped.

Murder

Grim Harvest

Return target creature card from your graveyard to your hand.
Recover {2}{B} (When a creature is put into your graveyard from the battlefield, you may pay {2}{B}. If you do, return this card from your graveyard to your hand. Otherwise, exile this card.)

Diabolic Intent

As an additional cost to cast this spell, sacrifice a creature.
Search your library for a card, put that card into your hand, then shuffle.

Gutless Ghoul

{1}, Sacrifice a creature: You gain 2 life.

Demonic Collusion

Buyback—Discard two cards. (You may discard two cards in addition to any other costs as you cast this spell. If you do, put this card into your hand as it resolves.)
Search your library for a card, put that card into your hand, then shuffle.

Bone Shards

As an additional cost to cast this spell, sacrifice a creature or discard a card.
Destroy target creature or planeswalker.

Aphetto Dredging

Return up to three target creature cards of the creature type of your choice from your graveyard to your hand.

Bladebrand

Target creature gains deathtouch until end of turn.
Draw a card.

Asphyxiate

Cabal Interrogator

{X}{B}, {T}: Target player reveals X cards from their hand and you choose one of them. That player discards that card. Activate only as a sorcery.

Cemetery Recruitment

Return target creature card from your graveyard to your hand. If it's a Zombie card, draw a card.

Gravebane Zombie

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

Increasing Ambition

Search your library for a card and put that card into your hand. If this spell was cast from a graveyard, instead search your library for two cards and put those cards into your hand. Then shuffle.
Flashback {7}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Death Tyrant

Menace
Negative Energy Cone — Whenever an attacking creature you control or a blocking creature an opponent controls dies, create a 2/2 black Zombie creature token.
{5}{B}: Return Death Tyrant from your graveyard to the battlefield tapped.

5 - land

Swamp

Darkness

Prevent all combat damage that would be dealt this turn.

Duress

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.

Assassinate

Ghastly Remains

Amplify 1 (As this creature enters, put a +1/+1 counter on it for each Zombie card you reveal in your hand.)
At the beginning of your upkeep, if Ghastly Remains is in your graveyard, you may pay {B}{B}{B}. If you do, return Ghastly Remains to your hand.

Persistent Specimen

{2}{B}: Return Persistent Specimen from your graveyard to the battlefield tapped.

Tenacious Dead

When Tenacious Dead dies, you may pay {1}{B}. If you do, return it to the battlefield tapped under its owner's control.

Costly Plunder

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards.

Pilfer

Impale

Ozox, the Clattering King

Ozox, the Clattering King can't block.
When Ozox dies, create Jumblebones, a legendary 2/1 black Skeleton creature token with "This creature can't block" and "When this creature leaves the battlefield, return target card named Ozox, the Clattering King from your graveyard to your hand."

Crypt Incursion

Exile all creature cards from target player's graveyard. You gain 3 life for each card exiled this way.

Hell's Caretaker

{T}, Sacrifice a creature: Return target creature card from your graveyard to the battlefield. Activate only during your upkeep.

Dread Charge

Black creatures you control can't be blocked this turn except by black creatures.

Grafted Butcher

When Grafted Butcher enters, Phyrexians you control gain menace until end of turn.
Other Phyrexians you control get +1/+1.
{3}{B}, Sacrifice an artifact or creature: Return Grafted Butcher from your graveyard to the battlefield. Activate only as a sorcery.

Aphotic Wisps

Target creature becomes black and gains fear until end of turn. (It can't be blocked except by artifact creatures and/or black creatures.)
Draw a card.

Boneknitter

{1}{B}: Regenerate target Zombie.
Morph {2}{B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Gixian Infiltrator

Whenever you sacrifice another permanent, put a +1/+1 counter on Gixian Infiltrator.

Pulling Teeth

Clash with an opponent. If you win, target player discards two cards. Otherwise, that player discards a card. (Each clashing player reveals the top card of their library, then puts that card on the top or bottom. A player wins if their card had a higher mana value.)

Festering Mummy

When Festering Mummy dies, you may put a -1/-1 counter on target creature.

Diabolic Edict

Target player sacrifices a creature of their choice.

Festering Goblin

When Festering Goblin dies, target creature gets -1/-1 until end of turn.

Deathmark Prelate

{2}{B}, {T}, Sacrifice a Zombie: Destroy target non-Zombie creature. It can't be regenerated. Activate only as a sorcery.