Mindleecher

Mutate {4}{B} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Flying
Whenever this creature mutates, exile the top card of each opponent's library face down. You may look at and play those cards for as long as they remain exiled.

Chainbreaker

This creature enters with two -1/-1 counters on it.
{3}, {T}: Remove a -1/-1 counter from target creature.

Collective Nightmare

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Target creature gets -3/-3 until end of turn.

Faceless Devourer

Shadow (This creature can block or be blocked by only creatures with shadow.)
When this creature enters, exile another target creature with shadow.
When this creature leaves the battlefield, return the exiled card to the battlefield under its owner's control.

Chainflail Centipede

Whenever this creature or equipped creature attacks, it gets +2/+0 until end of turn.
Reconfigure {2} ({2}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Chainflinger

{1}{R}, {T}: This creature deals 1 damage to any target.
Threshold — {2}{R}, {T}: This creature deals 2 damage to any target. Activate only if seven or more cards are in your graveyard.

Chains of Mephistopheles

If a player would draw a card except the first one they draw in each of their draw steps, that player discards a card instead. If the player discards a card this way, they draw a card. If the player doesn't discard a card this way, they mill a card.

Chainer, Nightmare Adept

Discard a card: You may cast a creature spell from your graveyard this turn. Activate only once each turn.
Whenever a nontoken creature you control enters, if you didn't cast it from your hand, it gains haste until your next turn.

Doom Whisperer

Flying, trample
Pay 2 life: Surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Hopeless Nightmare

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

Dreams of Steel and Oil

Target opponent reveals their hand. You choose an artifact or creature card from it, then choose an artifact or creature card from their graveyard. Exile the chosen cards.

The Chain Veil

At the beginning of your end step, if you didn't activate a loyalty ability of a planeswalker this turn, you lose 2 life.
{4}, {T}: For each planeswalker you control, you may activate one of its loyalty abilities once this turn as though none of its loyalty abilities have been activated this turn.

Nether Horror

Looming Shade

{B}: This creature gets +1/+1 until end of turn.

Nightmare Shepherd

Flying
Whenever another nontoken creature you control dies, you may exile it. If you do, create a token that's a copy of that creature, except it's 1/1 and it's a Nightmare in addition to its other types.

Chainer's Torment

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — This Saga deals 2 damage to each opponent and you gain 2 life.
III — Create an X/X black Nightmare Horror creature token, where X is half your life total, rounded up. It deals X damage to you.

Gravegouger

When this creature enters, exile up to two target cards from a single graveyard.
When this creature leaves the battlefield, return the exiled cards to their owner's graveyard.

Gibbering Barricade

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

Laquatus's Champion

When this creature enters, target player loses 6 life.
When this creature leaves the battlefield, that player gains 6 life.
{B}: Regenerate this creature.

Banehound

Gloom Pangolin

Gore-House Chainwalker

Unleash (You may have this creature enter with a +1/+1 counter on it. It can't block as long as it has a +1/+1 counter on it.)

Petravark

When this creature enters, exile target land.
When this creature leaves the battlefield, return the exiled card to the battlefield under its owner's control.

Gloomfang Mauler

Swampcycling {2} ({2}, Discard this card: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.)
Backup 2 (When this creature enters, put two +1/+1 counters on target creature. If that's another creature, it gains the following ability until end of turn.)
Menace

Chained Brute

This creature doesn't untap during your untap step.
{1}, Sacrifice another creature: Untap this creature. Activate only during your turn.

Labyrinth Raptor

Menace
Whenever a creature you control with menace becomes blocked, defending player sacrifices a creature of their choice that's blocking it.
{B}{R}: Creatures you control with menace get +1/+0 until end of turn.

Chain of Smog

Target player discards two cards. That player may copy this spell and may choose a new target for that copy.

Chainer, Dementia Master

All Nightmares get +1/+1.
{B}{B}{B}, Pay 3 life: Put target creature card from a graveyard onto the battlefield under your control. That creature is black and is a Nightmare in addition to its other creature types.
When Chainer leaves the battlefield, exile all Nightmares.

Elspeth's Nightmare

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Destroy target creature an opponent controls with power 2 or less.
II — Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.
III — Exile target opponent's graveyard.

Cacophony Unleashed

When this enchantment enters, if you cast it, destroy all nonenchantment creatures.
Whenever this enchantment or another enchantment you control enters, until end of turn, this enchantment becomes a legendary 6/6 Nightmare God creature with menace and deathtouch. It's still an enchantment.

Grave Consequences

Each player may exile any number of cards from their graveyard. Then each player loses 1 life for each card in their graveyard.
Draw a card.

Faceless Butcher

When this creature enters, exile another target creature.
When this creature leaves the battlefield, return the exiled card to the battlefield under its owner's control.

Haunt of the Dead Marshes

When this creature enters, scry 1.
{2}{B}: Return this card from your graveyard to the battlefield tapped. Activate only if you control a legendary creature.

Mountain

Swamp

Worldgorger Dragon

Flying, trample
When this creature enters, exile all other permanents you control.
When this creature leaves the battlefield, return the exiled cards to the battlefield under their owners' control.

Dread Presence

Whenever a Swamp you control enters, choose one —
• You draw a card and you lose 1 life.
• This creature deals 2 damage to any target and you gain 2 life.

Dungeon Shade

Flying
{B}: This creature gets +1/+1 until end of turn.

Chittering Harvester

Mutate {4}{B} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Whenever this creature mutates, each opponent sacrifices a creature of their choice.

Nightmare's Thirst

You gain 1 life. Target creature gets -X/-X until end of turn, where X is the amount of life you gained this turn.

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.

Falthis, Shadowcat Familiar

Commanders you control have menace and deathtouch.
Partner (You can have two commanders if both have partner.)

Hunted Nightmare

Menace
When this creature enters, target opponent puts a deathtouch counter on a creature they control.

Petradon

When this creature enters, exile two target lands.
When this creature leaves the battlefield, return the exiled cards to the battlefield under their owners' control.
{R}: This creature gets +1/+0 until end of turn.

Ashiok, Wicked Manipulator

If you would pay life while your library has at least that many cards in it, exile that many cards from the top of your library instead.
+1: Look at the top two cards of your library. Exile one of them and put the other into your hand.
−2: Create two 1/1 black Nightmare creature tokens with "At the beginning of combat on your turn, if a card was put into exile this turn, put a +1/+1 counter on this token."
−7: Target player exiles the top X cards of their library, where X is the total mana value of cards you own in exile.

Fallaji Chaindancer

{2}: This creature gains double strike until end of turn.

Carnival Hellsteed

First strike, haste
Unleash (You may have this creature enter with a +1/+1 counter on it. It can't block as long as it has a +1/+1 counter on it.)

Insatiable Hemophage

Mutate {2}{B} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Deathtouch
Whenever this creature mutates, each opponent loses X life and you gain X life, where X is the number of times this creature has mutated.

Chain Lightning

Chain Lightning deals 3 damage to any target. Then that player or that permanent's controller may pay {R}{R}. If the player does, they may copy this spell and may choose a new target for that copy.

Angel of Suffering

Flying
If damage would be dealt to you, prevent that damage and mill twice that many cards.

Braids, Arisen Nightmare

At the beginning of your end step, you may sacrifice an artifact, creature, enchantment, land, or planeswalker. If you do, each opponent may sacrifice a permanent of their choice that shares a card type with it. For each opponent who doesn't, that player loses 2 life and you draw a card.

Chainwhip Cyclops

{3}{R}: Target creature can't block this turn.

Hypnox

Flying
When this creature enters, if you cast it from your hand, exile all cards from target opponent's hand.
When this creature leaves the battlefield, return the exiled cards to their owner's hand.

Angrath, the Flame-Chained

+1: Each opponent discards a card and loses 2 life.
−3: Gain control of target creature until end of turn. Untap it. It gains haste until end of turn. Sacrifice it at the beginning of the next end step if it has mana value 3 or less.
−8: Each opponent loses life equal to the number of cards in their graveyard.

Mesmeric Fiend

When this creature enters, target opponent reveals their hand and you choose a nonland card from it. Exile that card.
When this creature leaves the battlefield, return the exiled card to its owner's hand.

Hell Mongrel

Discard a card: This creature 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.)

Zulaport Chainmage

Cohort — {T}, Tap an untapped Ally you control: Target opponent loses 2 life.

Chain Reaction

Chain Reaction deals X damage to each creature, where X is the number of creatures on the battlefield.

Goblin Chainwhirler

First strike
When this creature enters, it deals 1 damage to each opponent and each creature and planeswalker they control.

Chainer's Edict

Target player sacrifices a creature of their choice.
Flashback {5}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Chain of Plasma

Chain of Plasma deals 3 damage to any target. Then that player or that permanent's controller may discard a card. If the player does, they may copy this spell and may choose a new target for that copy.

Grimdancer

This creature enters with your choice of two different counters on it from among menace, deathtouch, and lifelink.

Cavern Whisperer

Mutate {3}{B} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Menace (This creature can't be blocked except by two or more creatures.)
Whenever this creature mutates, each opponent discards a card.

Chain Devil

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

Nightmare Lash

Equipped creature gets +1/+1 for each Swamp you control.
Equip—Pay 3 life. (Pay 3 life: Attach to target creature you control. Equip only as a sorcery. This card enters unattached and stays on the battlefield if the creature leaves.)