Viscera Seer

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

Soldevi Adnate

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

Sifter of Skulls

Devoid (This card has no color.)
Whenever another nontoken creature you control dies, create a 1/1 colorless Eldrazi Scion creature token. It has "Sacrifice this creature: Add {C}." ({C} represents colorless mana.)

Blood Pet

Overeager Apprentice

Discard a card, Sacrifice Overeager Apprentice: Add {B}{B}{B}.

Bile Urchin

Sacrifice Bile Urchin: Target player loses 1 life.

Weaponcraft Enthusiast

Fabricate 2 (When this creature enters, put two +1/+1 counters on it or create two 1/1 colorless Servo artifact creature tokens.)

Bloodthrone Vampire

Sacrifice a creature: Bloodthrone Vampire gets +2/+2 until end of turn.

Myr Moonvessel

Death Cultist

Sacrifice Death Cultist: Target player loses 1 life and you gain 1 life.

Infectious Host

When Infectious Host dies, target player loses 2 life.

Lightning Coils

Whenever a nontoken creature you control dies, put a charge counter on Lightning Coils.
At the beginning of your upkeep, if Lightning Coils has five or more charge counters on it, remove all of them from it and create that many 3/1 red Elemental creature tokens with haste. Exile them at the beginning of the next end step.

Carrion Feeder

Carrion Feeder can't block.
Sacrifice a creature: Put a +1/+1 counter on Carrion Feeder.

Smothering Abomination

Devoid (This card has no color.)
Flying
At the beginning of your upkeep, sacrifice a creature.
Whenever you sacrifice a creature, draw a card.

Basal Thrull

Deathgreeter

Whenever another creature dies, you may gain 1 life.

Skyscanner

Flying
When Skyscanner enters, draw a card.

Blood Artist

Whenever Blood Artist or another creature dies, target player loses 1 life and you gain 1 life.

Shirei, Shizo's Caretaker

Whenever a creature with power 1 or less is put into your graveyard from the battlefield, you may return that card to the battlefield at the beginning of the next end step if Shirei, Shizo's Caretaker is still on the battlefield.

Kalastria Healer

Rally — Whenever Kalastria Healer or another Ally you control enters, each opponent loses 1 life and you gain 1 life.

Falkenrath Noble

Flying
Whenever Falkenrath Noble or another creature dies, target player loses 1 life and you gain 1 life.

Midnight Reaper

Whenever a nontoken creature you control dies, Midnight Reaper deals 1 damage to you and you draw a card.

Mindless Automaton

Mindless Automaton enters with two +1/+1 counters on it.
{1}, Discard a card: Put a +1/+1 counter on Mindless Automaton.
Remove two +1/+1 counters from Mindless Automaton: Draw a card.

Krav, the Unredeemed

Partner with Regna, the Redeemer (When this creature enters, target player may put Regna into their hand from their library, then shuffle.)
{B}, Sacrifice X creatures: Target player draws X cards and gains X life. Put X +1/+1 counters on Krav, the Unredeemed.

Blessing of Leeches

Flash
Enchant creature
At the beginning of your upkeep, you lose 1 life.
{0}: Regenerate enchanted creature.

Gray Merchant of Asphodel

When Gray Merchant of Asphodel 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.)

Perilous Myr

When Perilous Myr dies, it deals 2 damage to any target.

Ogre Slumlord

Whenever another nontoken creature dies, you may create a 1/1 black Rat creature token.
Rats you control have deathtouch.

Pawn of Ulamog

Whenever Pawn of Ulamog or another nontoken creature you control dies, you may create a 0/1 colorless Eldrazi Spawn creature token. It has "Sacrifice this creature: Add {C}."

Bone Shredder

Flying
Echo {2}{B} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When Bone Shredder enters, destroy target nonartifact, nonblack creature.

Abyssal Gatekeeper

When Abyssal Gatekeeper dies, each player sacrifices a creature.

Open the Graves

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

Butcher of Malakir

Flying
Whenever Butcher of Malakir or another creature you control dies, each opponent sacrifices a creature.

Sultai Emissary

When Sultai Emissary dies, manifest the top card of your library. (Put that card onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)

Swamp

Fume Spitter

Sacrifice Fume Spitter: Put a -1/-1 counter on target creature.

Desecrated Tomb

Whenever one or more creature cards leave your graveyard, create a 1/1 black Bat creature token with flying.

Dark Privilege

Enchant creature
Enchanted creature gets +1/+1.
Sacrifice a creature: Regenerate enchanted creature.

Tattered Mummy

When Tattered Mummy dies, each opponent loses 2 life.

Apprentice Necromancer

{B}, {T}, Sacrifice Apprentice Necromancer: Return target creature card from your graveyard to the battlefield. That creature gains haste. At the beginning of the next end step, sacrifice it.

Pitiless Plunderer

Whenever another creature you control dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Doomed Dissenter

When Doomed Dissenter dies, create a 2/2 black Zombie creature token.

Thoughtpicker Witch

{1}, Sacrifice a creature: Look at the top two cards of target opponent's library, then exile one of them.

Grim Haruspex

Morph {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.)
Whenever another nontoken creature you control dies, draw a card.

Wake the Dead

Cast this spell only during combat on an opponent's turn.
Return X target creature cards from your graveyard to the battlefield. Sacrifice those creatures at the beginning of the next end step.

Gleaming Barrier

Defender
When Gleaming Barrier dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Dark Prophecy

Whenever a creature you control dies, you draw a card and you lose 1 life.

Cadaver Imp

Flying
When Cadaver Imp enters, you may return target creature card from your graveyard to your hand.

Marionette Master

Fabricate 3 (When this creature enters, put three +1/+1 counters on it or create three 1/1 colorless Servo artifact creature tokens.)
Whenever an artifact you control is put into a graveyard from the battlefield, target opponent loses life equal to Marionette Master's power.

Genesis Chamber

Whenever a nontoken creature enters, if Genesis Chamber is untapped, that creature's controller creates a 1/1 colorless Myr artifact creature token.

Ashnod's Altar

Spawning Pit

Sacrifice a creature: Put a charge counter on Spawning Pit.
{1}, Remove two charge counters from Spawning Pit: Create a 2/2 colorless Spawn artifact creature token.

Cloak and Dagger

Equipped creature gets +2/+0 and has shroud. (It can't be the target of spells or abilities.)
Whenever a Rogue creature enters, you may attach Cloak and Dagger to it.
Equip {3}

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Myr Sire

When Myr Sire dies, create a 1/1 colorless Phyrexian Myr artifact creature token.

Dusk Legion Zealot

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

Leaden Myr

Marsh Flitter

Flying
When Marsh Flitter enters, create two 1/1 black Goblin Rogue creature tokens.
Sacrifice a Goblin: Marsh Flitter has base power and toughness 3/3 until end of turn.

Zulaport Cutthroat

Whenever Zulaport Cutthroat or another creature you control dies, each opponent loses 1 life and you gain 1 life.

Mask of Avacyn

Equipped creature gets +1/+2 and has hexproof. (It can't be the target of spells or abilities your opponents control.)
Equip {3}

Pilgrim's Eye

Flying
When Pilgrim's Eye enters, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Skittering Surveyor

When Skittering Surveyor enters, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Qarsi Sadist

Exploit (When this creature enters, you may sacrifice a creature.)
When Qarsi Sadist exploits a creature, target opponent loses 2 life and you gain 2 life.