Ichor Rats

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
When Ichor Rats enters, each player gets a poison counter.

Contagious Nim

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Gutless Ghoul

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

Killing Wave

For each creature, its controller sacrifices it unless they pay X life.

Bladewing's Thrall

Bladewing's Thrall has flying as long as you control a Dragon.
When a Dragon enters, you may return Bladewing's Thrall from your graveyard to the battlefield.

Ensnaring Bridge

Creatures with power greater than the number of cards in your hand can't attack.

Phyrexian Rager

When Phyrexian Rager enters, you draw a card and you lose 1 life.

Skeletal Scrying

As an additional cost to cast this spell, exile X cards from your graveyard.
You draw X cards and you lose X life.

Unspeakable Symbol

Pay 3 life: Put a +1/+1 counter on target creature.

Ichorclaw Myr

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Whenever Ichorclaw Myr becomes blocked, it gets +2/+2 until end of turn.

Sign in Blood

Target player draws two cards and loses 2 life.

Living Death

Each player exiles all creature cards from their graveyard, then sacrifices all creatures they control, then puts all cards they exiled this way onto the battlefield.

Go for the Throat

Twisted Abomination

{B}: Regenerate Twisted Abomination. (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.)

Hand of the Praetors

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Other creatures you control with infect get +1/+1.
Whenever you cast a creature spell with infect, target player gets a poison counter.

Skulltap

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

Swamp

Phyrexian Obliterator

Trample
Whenever a source deals damage to Phyrexian Obliterator, that source's controller sacrifices that many permanents of their choice.

Altar's Reap

Blightsteel Colossus

Trample, infect, indestructible
If Blightsteel Colossus would be put into a graveyard from anywhere, reveal Blightsteel Colossus and shuffle it into its owner's library instead.

Flensermite

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

It That Betrays

Annihilator 2 (Whenever this creature attacks, defending player sacrifices two permanents of their choice.)
Whenever an opponent sacrifices a nontoken permanent, put that card onto the battlefield under your control.

Massacre Wurm

When this creature enters, creatures your opponents control get -2/-2 until end of turn.
Whenever a creature an opponent controls dies, that player loses 2 life.

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.)

Tragic Slip

Target creature gets -1/-1 until end of turn.
Morbid — That creature gets -13/-13 until end of turn instead if a creature died this turn.

Exsanguinate

Each opponent loses X life. You gain life equal to the life lost this way.

Phyrexian Arena

At the beginning of your upkeep, you draw a card and you lose 1 life.

Hideous End

Destroy target nonblack creature. Its controller loses 2 life.

Zombie Infestation

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

Dead Weight

Enchant creature
Enchanted creature gets -2/-2.

Syphon Mind

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

Vampiric Rites

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

Sangromancer

Flying
Whenever a creature an opponent controls dies, you may gain 3 life.
Whenever an opponent discards a card, you may gain 3 life.

Strata Scythe

Imprint — When Strata Scythe enters, search your library for a land card, exile it, then shuffle.
Equipped creature gets +1/+1 for each land on the battlefield with the same name as the exiled card.
Equip {3}

Contaminated Ground

Enchant land
Enchanted land is a Swamp.
Whenever enchanted land becomes tapped, its controller loses 2 life.

Oona's Blackguard

Flying
Each other Rogue creature you control enters with an additional +1/+1 counter on it.
Whenever a creature you control with a +1/+1 counter on it deals combat damage to a player, that player discards a card.

Festering Goblin

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

Big Game Hunter

When Big Game Hunter enters, destroy target creature with power 4 or greater. It can't be regenerated.
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.)

Infiltration Lens

Whenever equipped creature becomes blocked by a creature, you may draw two cards.
Equip {1}

Whispersilk Cloak

Equipped creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)
Equip {2}

Doom Blade

Nantuko Husk

Sacrifice a creature: Nantuko Husk gets +2/+2 until end of turn.

Grisly Spectacle

Destroy target nonartifact creature. Its controller mills cards equal to that creature's power.

Grave Pact

Whenever a creature you control dies, each other player sacrifices a creature of their choice.

Nighthaze

Target creature gains swampwalk until end of turn. (It can't be blocked as long as defending player controls a Swamp.)
Draw a card.

Plague Stinger

Flying
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Phyrexian Crusader

First strike, protection from red and from white
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Mutilate

All creatures get -1/-1 until end of turn for each Swamp you control.

Diabolic Tutor

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

Death Cloud

Each player loses X life, discards X cards, sacrifices X creatures of their choice, then sacrifices X lands of their choice.

Virulent Wound

Put a -1/-1 counter on target creature. When that creature dies this turn, its controller gets a poison counter.

Trespasser il-Vec

Discard a card: Trespasser il-Vec gains shadow until end of turn. (It can block or be blocked by only creatures with shadow.)

Mind Sludge

Target player discards a card for each Swamp you control.

Vampire Nighthawk

Flying
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Order of Yawgmoth

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Whenever Order of Yawgmoth deals damage to a player, that player discards a card.

Endless Ranks of the Dead

At the beginning of your upkeep, create X 2/2 black Zombie creature tokens, where X is half the number of Zombies you control, rounded down.

Strength of Lunacy

Enchant creature
Enchanted creature gets +2/+1 and has protection from white.
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.)

Death's Approach

Enchant creature
Enchanted creature gets -X/-X, where X is the number of creature cards in its controller's graveyard.

Consume the Meek

Destroy each creature with mana value 3 or less. They can't be regenerated.

Skullclamp

Equipped creature gets +1/-1.
Whenever equipped creature dies, draw two cards.
Equip {1}

Skithiryx, the Blight Dragon

Flying
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
{B}: Skithiryx, the Blight Dragon gains haste until end of turn.
{B}{B}: Regenerate Skithiryx.

Tainted Strike

Target creature gets +1/+0 and gains infect until end of turn. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)