Ravenous Rats

When Ravenous Rats enters the battlefield, target opponent discards a card.

Shambling Attendants

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Deep Goblin Skulltaker

Menace
At the beginning of your end step, if you descended this turn, put a +1/+1 counter on Deep Goblin Skulltaker. (You descended if a permanent card was put into your graveyard from anywhere.)

Witch's Cottage

({T}: Add {B}.)
Witch's Cottage enters the battlefield tapped unless you control three or more other Swamps.
When Witch's Cottage enters the battlefield untapped, you may put target creature card from your graveyard on top of your library.

Dregscape Zombie

Unearth {B} ({B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Urza's Tower

{T}: Add {C}. If you control an Urza's Mine and an Urza's Power-Plant, add {C}{C}{C} instead.

Expedition Map

{2}, {T}, Sacrifice Expedition Map: Search your library for a land card, reveal it, put it into your hand, then shuffle.

Changeling Outcast

Changeling (This card is every creature type.)
Changeling Outcast can't block and can't be blocked.

Entropic Decay

Mill four cards. (Then exile this card. You may cast the creature later from exile.)

Gray Slaad

As long as there are four or more creature cards in your graveyard, Gray Slaad has menace and deathtouch.

Gray Slaad // Entropic Decay

Infectious Inquiry

You draw two cards and you lose 2 life. Each opponent gets a poison counter.

Grave Scrabbler

Madness {1}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)
When Grave Scrabbler enters the battlefield, if its madness cost was paid, you may return target creature card from a graveyard to its owner's hand.

Rancid Earth

Destroy target land.
Threshold — If seven or more cards are in your graveyard, instead destroy that land and Rancid Earth deals 1 damage to each creature and each player.

Weirded Vampire

Madness {2}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Brain Gorgers

When you cast this spell, any player may sacrifice a creature. If a player does, counter Brain Gorgers.
Madness {1}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Lotus Petal

{T}, Sacrifice Lotus Petal: Add one mana of any color.

Deadly Dispute

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Bog Witch

Burglar Rat

When Burglar Rat enters the battlefield, each opponent discards a card.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Snuff Out

If you control a Swamp, you may pay 4 life rather than pay this spell's mana cost.
Destroy target nonblack creature. It can't be regenerated.

Psychotic Haze

Psychotic Haze deals 1 damage to each creature and each player.
Madness {1}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Sultai Scavenger

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Flying

Death Rattle

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Destroy target nongreen creature. It can't be regenerated.

Scrapwork Rager

When Scrapwork Rager enters the battlefield, you draw a card and you lose 1 life.
Unearth {3}{B} ({3}{B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Bone Shards

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

Cauldron Familiar

When Cauldron Familiar enters the battlefield, each opponent loses 1 life and you gain 1 life.
Sacrifice a Food: Return Cauldron Familiar from your graveyard to the battlefield.

Dirty Wererat

{B}, Discard a card: Regenerate Dirty Wererat.
Threshold — As long as seven or more cards are in your graveyard, Dirty Wererat gets +2/+2 and can't block.

Gurmag Angler

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)

Alms of the Vein

Target opponent loses 3 life and you gain 3 life.
Madness {B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Infernal Idol

{T}: Add {B}.
{1}{B}{B}, {T}, Sacrifice Infernal Idol: You draw two cards and you lose 2 life.

Hopeless Nightmare

When Hopeless Nightmare enters the battlefield, each opponent discards a card and loses 2 life.
When Hopeless Nightmare is put into a graveyard from the battlefield, scry 2.
{2}{B}: Sacrifice Hopeless Nightmare.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Polluted Mire

Polluted Mire enters the battlefield tapped.
{T}: Add {B}.
Cycling {2} ({2}, Discard this card: Draw a card.)

Consuming Sepulcher

At the beginning of your upkeep, each opponent loses 1 life and you gain 1 life.

Tithing Blade

When Tithing Blade enters the battlefield, each opponent sacrifices a creature.
Craft with creature {4}{B} ({4}{B}, Exile this artifact, Exile a creature you control or a creature card from your graveyard: Return this card transformed under its owner's control. Craft only as a sorcery.)

Tithing Blade // Consuming Sepulcher

Dark Withering

Destroy target nonblack creature.
Madness {B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Urza's Mine

{T}: Add {C}. If you control an Urza's Power-Plant and an Urza's Tower, add {C}{C} instead.

Viscera Dragger

Cycling {2} ({2}, Discard this card: Draw a card.)
Unearth {1}{B} ({1}{B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Gixian Skullflayer

At the beginning of your upkeep, if there are three or more creature cards in your graveyard, put a +1/+1 counter on Gixian Skullflayer.

Swamp

Liliana's Elite

Liliana's Elite gets +1/+1 for each creature card in your graveyard.

Village Rites

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

Twins of Maurer Estate

Dross Skullbomb

{1}, Sacrifice Dross Skullbomb: Draw a card.
{2}{B}, Sacrifice Dross Skullbomb: Return target creature card from your graveyard to your hand. Draw a card. Activate only as a sorcery.

Tortured Existence

{B}, Discard a creature card: Return target creature card from your graveyard to your hand.

Putrid Imp

Discard a card: Putrid Imp gains flying until end of turn.
Threshold — As long as seven or more cards are in your graveyard, Putrid Imp gets +1/+1 and can't block.

Frightcrawler

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Threshold — As long as seven or more cards are in your graveyard, Frightcrawler gets +2/+2 and can't block.

Psychotic Episode

Target player reveals their hand and the top card of their library. You choose a card revealed this way. That player puts the chosen card on the bottom of their library.
Madness {1}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Dark Ritual

Dusk Legion Zealot

When Dusk Legion Zealot enters the battlefield, you draw a card and you lose 1 life.

Wight of Precinct Six

Wight of Precinct Six gets +1/+1 for each creature card in your opponents' graveyards.

Urza's Power Plant

{T}: Add {C}. If you control an Urza's Mine and an Urza's Tower, add {C}{C} instead.

Liliana's Specter

Flying
When Liliana's Specter enters the battlefield, each opponent discards a card.

Mortuary Mire

Mortuary Mire enters the battlefield tapped.
When Mortuary Mire enters the battlefield, you may put target creature card from your graveyard on top of your library.
{T}: Add {B}.

Ichor Slick

Target creature gets -3/-3 until end of turn.
Cycling {2} ({2}, Discard this card: Draw a card.)
Madness {3}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Undertaker

{B}, {T}, Discard a card: Return target creature card from your graveyard to your hand.

Toxic Stench

Target nonblack creature gets -1/-1 until end of turn.
Threshold — If seven or more cards are in your graveyard, instead destroy that creature. It can't be regenerated.

Virus Beetle

When Virus Beetle enters the battlefield, each opponent discards a card.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Kitchen Imp

Flying, haste
Madness {B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Necrogen Spellbomb

{B}, Sacrifice Necrogen Spellbomb: Target player discards a card.
{1}, Sacrifice Necrogen Spellbomb: Draw a card.

Creeping Bloodsucker

At the beginning of your upkeep, Creeping Bloodsucker deals 1 damage to each opponent. You gain life equal to the damage dealt this way.

Cabal Ritual

Add {B}{B}{B}.
Threshold — Add {B}{B}{B}{B}{B} instead if seven or more cards are in your graveyard.

Skirge Familiar

Gorgon Recluse

Whenever Gorgon Recluse blocks or becomes blocked by a nonblack creature, destroy that creature at end of combat.
Madness {B}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Call to the Netherworld

Return target black creature card from your graveyard to your hand.
Madness {0} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Sign in Blood

Target player draws two cards and loses 2 life.

Hell Mongrel

Discard a card: Hell Mongrel gets +1/+1 until end of turn.
Madness {2}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Horror of the Broken Lands

Whenever you cycle or discard another card, Horror of the Broken Lands gets +2/+1 until end of turn.
Cycling {B} ({B}, Discard this card: Draw a card.)

Syphon Mind

Each other player discards a card. You draw a card for each card discarded this way.

Gray Merchant of Asphodel

When Gray Merchant of Asphodel enters the battlefield, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Murderous Compulsion

Destroy target tapped creature.
Madness {1}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Echo of Dusk

Descend 4 — As long as there are four or more permanent cards in your graveyard, Echo of Dusk gets +1/+1 and has lifelink.