Have

Dimir House Guard

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Sacrifice a creature: Regenerate this creature.
Transmute {1}{B}{B} ({1}{B}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Basal Thrull

{T}, Sacrifice this creature: Add {B}{B}.

Innocuous Rat

When this creature dies, manifest dread. (Look at the top two cards of your library. Put one onto the battlefield face down as a 2/2 creature and the other into your graveyard. Turn it face up any time for its mana cost if it's a creature card.)

Demonic Vigor

Enchant creature
Enchanted creature gets +1/+1.
When enchanted creature dies, return that card to its owner's hand.

Corrupted Conviction

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

Street Wraith

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
Cycling—Pay 2 life. (Pay 2 life, Discard this card: Draw a card.)

Ashnod's Altar

Carrion Feeder

This creature can't block.
Sacrifice a creature: Put a +1/+1 counter on this creature.

Hunt for Specimens

Create a 1/1 black and green Pest creature token with "When this token dies, you gain 1 life."
Learn. (You may reveal a Lesson card you own from outside the game and put it into your hand, or discard a card to draw a card.)

Not Dead After All

Until end of turn, target creature you control gains "When this creature dies, return it to the battlefield tapped under its owner's control, then create a Wicked Role token attached to it." (Enchanted creature gets +1/+1. When this token is put into a graveyard, each opponent loses 1 life.)

Gray Merchant of Asphodel

When this creature enters, 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.)

Feign Death

Until end of turn, target creature gains "When this creature dies, return it to the battlefield tapped under its owner's control with a +1/+1 counter on it."

Chitin Gravestalker

This spell costs {1} less to cast for each artifact and/or creature card in your graveyard.
Cycling {2} ({2}, Discard this card: Draw a card.)

Gibbering Barricade

Defender
{2}{B}, Sacrifice a creature: You gain 1 life and draw a card.

Writhing Necromass

This spell costs {1} less to cast for each creature card in your graveyard.
Deathtouch

Pestilence

At the beginning of the end step, if no creatures are on the battlefield, sacrifice this enchantment.
{B}: This enchantment deals 1 damage to each creature and each player.

Malboro

Bad Breath — When this creature enters, each opponent discards a card, loses 2 life, and exiles the top three cards of their library.
Swampcycling {2} ({2}, Discard this card: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.)

Summon Undead

You may mill three cards. Then return a creature card from your graveyard to the battlefield. (To mill a card, put the top card of your library into your graveyard.)

Syphon Mind

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

Overwhelming Remorse

This spell costs {1} less to cast for each creature card in your graveyard.
Exile target creature or planeswalker.

Underdark Explorer

Menace (This creature can't be blocked except by two or more creatures.)
When this creature enters, you take the initiative.

Gempalm Polluter

Cycling {B}{B} ({B}{B}, Discard this card: Draw a card.)
When you cycle this card, you may have target player lose life equal to the number of Zombies on the battlefield.

Swamp

Cabal Ritual

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

Blood Pet

Shred Memory

Exile up to four target cards from a single graveyard.
Transmute {1}{B}{B} ({1}{B}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Viscera Seer

Sacrifice a creature: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Supernatural Stamina

Until end of turn, target creature gets +2/+0 and gains "When this creature dies, return it to the battlefield tapped under its owner's control."

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, this creature has menace and deathtouch.

Gray Slaad // Entropic Decay

Slice from the Shadows

This spell can't be countered. (This includes by the ward ability.)
Target creature gets -X/-X until end of turn.

Worthy Cost

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

Lotleth Giant

Undergrowth — When this creature enters, it deals 1 damage to target opponent for each creature card in your graveyard.

Dread Return

Return target creature card from your graveyard to the battlefield.
Flashback—Sacrifice three creatures. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Read the Bones

Scry 2, then draw two cards. You lose 2 life. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Canyon Crawler

Deathtouch
When this creature enters, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")
Swampcycling {2} ({2}, Discard this card: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.)

Discerning Taste

Look at the top four cards of your library. Put one of them into your hand and the rest into your graveyard. You gain life equal to the greatest power among creature cards put into your graveyard this way.

Fake Your Own Death

Until end of turn, target creature gets +2/+0 and gains "When this creature dies, return it to the battlefield tapped under its owner's control and you create a Treasure token." (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Lurching Rotbeast

Cycling {B} ({B}, Discard this card: Draw a card.)

Wasteland Scorpion

Deathtouch
Cycling {2} ({2}, Discard this card: Draw a card.)

Accursed Marauder

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

Tendrils of Corruption

Tendrils of Corruption deals X damage to target creature and you gain X life, where X is the number of Swamps you control.

Corpse Churn

Mill three cards, then you may return a creature card from your graveyard to your hand. (To mill three cards, put the top three cards of your library into your graveyard.)

Kaya's Ghostform

Enchant creature or planeswalker you control
When enchanted permanent dies or is put into exile, return that card to the battlefield under your control.

Mind Rake

Target player discards two cards.
Overload {1}{B} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Abnormal Endurance

Resentful Revelation

Look at the top three cards of your library. Put one of them into your hand and the rest into your graveyard.
Flashback {6}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Horror of the Broken Lands

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

Moaning Wall

Defender
Cycling {2} ({2}, Discard this card: Draw a card.)

Hollow Marauder

This spell costs {1} less to cast for each creature card in your graveyard.
Flying
When this creature enters, any number of target opponents each discard a card. For each of those opponents who didn't discard a card with mana value 4 or greater, draw a card.

Defile

Target creature gets -1/-1 until end of turn for each Swamp you control.

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 token: Add one mana of any color.")

Corrupt

Corrupt deals damage to any target equal to the number of Swamps you control. You gain life equal to the damage dealt this way.

Dark Ritual

Crow of Dark Tidings

Flying
When this creature enters or dies, mill two cards. (Put the top two cards of your library into your graveyard.)

Faerie Macabre

Flying
Discard this card: Exile up to two target cards from graveyards.

Songs of the Damned

Add {B} for each creature card in your graveyard.

Innocent Blood

Each player sacrifices a creature of their choice.

Ob Nixilis's Cruelty

Target creature gets -5/-5 until end of turn. If that creature would die this turn, exile it instead.

Twisted Abomination

{B}: Regenerate this creature. (The next time this creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)
Swampcycling {2} ({2}, Discard this card: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.)

Soldevi Adnate

{T}, Sacrifice a black or artifact creature: Add an amount of {B} equal to the sacrificed creature's mana value.

Oubliette

When this enchantment enters, target creature phases out until this enchantment leaves the battlefield. Tap that creature as it phases in this way. (Auras and Equipment phase out with it. While permanents are phased out, they're treated as though they don't exist.)

Fleshbag Marauder

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

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.

Ransack the Lab

Look at the top three cards of your library. Put one of them into your hand and the rest into your graveyard.

Crypt Rats

{X}: This creature deals X damage to each creature and each player. Spend only black mana on X.