Signal Pest

Battle cry (Whenever this creature attacks, each other attacking creature gets +1/+0 until end of turn.)
Signal Pest can't be blocked except by creatures with flying or reach.

Hedron Crawler

{T}: Add {C}. ({C} represents colorless mana.)

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.

Bonesplitter

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.)

Barren Moor

Barren Moor enters tapped.
{T}: Add {B}.
Cycling {B} ({B}, Discard this card: Draw a card.)

Paragon of Open Graves

Other black creatures you control get +1/+1.
{2}{B}, {T}: Another target black creature you control gains deathtouch until end of turn. (Any amount of damage it deals to a creature is enough to destroy it.)

Phyresis

Enchant creature
Enchanted creature has infect. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Quag Sickness

Enchant creature
Enchanted creature gets -1/-1 for each Swamp you control.

Knight of Infamy

Protection from white (This creature can't be blocked, targeted, dealt damage, or enchanted by anything white.)
Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)

Swamp

Everflowing Chalice

Multikicker {2} (You may pay an additional {2} any number of times as you cast this spell.)
Everflowing Chalice enters with a charge counter on it for each time it was kicked.
{T}: Add {C} for each charge counter on Everflowing Chalice.

Midnight Reaper

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

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.

Fireshrieker

Equipped creature has double strike. (It deals both first-strike and regular combat damage.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Fleshbag Marauder

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

Duty-Bound Dead

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
{3}{B}: Regenerate Duty-Bound Dead. (The next time this creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Plaguecrafter

When Plaguecrafter enters, each player sacrifices a creature or planeswalker of their choice. Each player who can't discards a card.

Pristine Talisman

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Head Games

Target opponent puts the cards from their hand on top of their library. Search that player's library for that many cards. The player puts those cards into their hand, then shuffles.

Charcoal Diamond

Charcoal Diamond enters tapped.
{T}: Add {B}.

Phyrexian Digester

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

Sign in Blood

Target player draws two cards and loses 2 life.

Duskmantle Prowler

Haste (This creature can attack and {T} as soon as it comes under your control.)
Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)

Alloy Myr

Phyrexian Juggernaut

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Phyrexian Juggernaut attacks each combat if able.

Darksteel Axe

Indestructible (Effects that say "destroy" don't destroy this artifact.)
Equipped creature gets +2/+0.
Equip {2}

Merciless Executioner

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

Skeleton Shard

{3}, {T} or {B}, {T}: Return target artifact creature card from your graveyard to your hand.

Sol Ring

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.)

Darksteel Citadel

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.)

Bojuka Bog

Bojuka Bog enters tapped.
When Bojuka Bog enters, exile target player's graveyard.
{T}: Add {B}.

Hissing Miasma

Whenever a creature attacks you, its controller loses 1 life.

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.)

Sever the Bloodline

Exile target creature and all other creatures with the same name as that creature.
Flashback {5}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Go for the Throat

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.)

Cranial Plating

Equipped creature gets +1/+0 for each artifact you control.
{B}{B}: Attach Cranial Plating to target creature you control.
Equip {1}

Rise from the Grave

Put target creature card from a graveyard onto the battlefield under your control. That creature is a black Zombie in addition to its other colors and types.

Plague Myr

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
{T}: Add {C}.

Snake Cult Initiation

Enchant creature
Enchanted creature has poisonous 3. (Whenever it deals combat damage to a player, that player gets three poison counters. A player with ten or more poison counters loses the game.)

Custodi Lich

When Custodi Lich enters, you become the monarch.
Whenever you become the monarch, target player sacrifices a creature of their choice.

Servant of Nefarox

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)

Demon's Disciple

When Demon's Disciple enters, each player sacrifices a creature or planeswalker of their choice.

Whispering Specter

Flying
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Whenever Whispering Specter deals combat damage to a player, you may sacrifice it. If you do, that player discards a card for each poison counter they have.

Whispersilk Cloak

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

Withengar Unbound

Flying, intimidate, trample (A creature with intimidate can't be blocked except by artifact creatures and/or creatures that share a color with it.)
Whenever a player loses the game, put thirteen +1/+1 counters on Withengar Unbound.

Elbrus, the Binding Blade

Equipped creature gets +1/+0.
When equipped creature deals combat damage to a player, unattach Elbrus, the Binding Blade, then transform it.
Equip {1}

Elbrus, the Binding Blade // Withengar Unbound

Dark Favor

Enchant creature
When Dark Favor enters, you lose 1 life.
Enchanted creature gets +3/+1.

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.

Ring of Xathrid

{2}: Regenerate equipped creature. (The next time that creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)
At the beginning of your upkeep, put a +1/+1 counter on equipped creature if it's black.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Expedition Map

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

Polluted Mire

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

Necrosynthesis

Enchant creature
Enchanted creature has "Whenever another creature dies, put a +1/+1 counter on this creature."
When enchanted creature dies, look at the top X cards of your library, where X is its power. Put one of those cards into your hand and the rest on the bottom of your library in a random order.

Leaden Myr

Nekrataal

First strike
When Nekrataal enters, destroy target nonartifact, nonblack creature. That creature can't be regenerated.

Word of Binding

Lost Vale

(Transforms from Dowsing Dagger.)
{T}: Add three mana of any one color.

Dowsing Dagger

When Dowsing Dagger enters, target opponent creates two 0/2 green Plant creature tokens with defender.
Equipped creature gets +2/+1.
Whenever equipped creature deals combat damage to a player, you may transform Dowsing Dagger.
Equip {2}

Dowsing Dagger // Lost Vale

Nightmare

Flying (This creature can't be blocked except by creatures with flying or reach.)
Nightmare's power and toughness are each equal to the number of Swamps you control.

Syphon Mind

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

Dark Ritual

Ashes to Ashes

Exile two target nonartifact creatures. Ashes to Ashes deals 5 damage to you.

Doom Blade

Underworld Dreams

Whenever an opponent draws a card, Underworld Dreams deals 1 damage to that player.

Murder

Squelching Leeches

Squelching Leeches's power and toughness are each equal to the number of Swamps you control.

Nefarox, Overlord of Grixis

Flying
Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
Whenever Nefarox, Overlord of Grixis attacks alone, defending player sacrifices a creature of their choice.

Core Prowler

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
When Core Prowler dies, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)