Cosmic Horror

First strike
At the beginning of your upkeep, destroy Cosmic Horror unless you pay {3}{B}{B}{B}. If Cosmic Horror is destroyed this way, it deals 7 damage to you.

Bad Moon

Morkrut Banshee

Morbid — When Morkrut Banshee enters the battlefield, if a creature died this turn, target creature gets -4/-4 until end of turn.

Extricator of Flesh

Eldrazi you control have vigilance.
{2}, {T}, Sacrifice a non-Eldrazi creature: Create a 3/2 colorless Eldrazi Horror creature token.

Extricator of Sin

When Extricator of Sin enters the battlefield, you may sacrifice another permanent. If you do, create a 3/2 colorless Eldrazi Horror creature token.
Delirium — At the beginning of your upkeep, if there are four or more card types among cards in your graveyard, transform Extricator of Sin.

Extricator of Sin // Extricator of Flesh

Massacre Girl

Menace
When Massacre Girl enters the battlefield, each other creature gets -1/-1 until end of turn. Whenever a creature dies this turn, each creature other than Massacre Girl gets -1/-1 until end of turn.

Mutilate

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

Stalking Vampire

At the beginning of your upkeep, you may pay {2}{B}{B}. If you do, transform Stalking Vampire.

Screeching Bat

Flying
At the beginning of your upkeep, you may pay {2}{B}{B}. If you do, transform Screeching Bat.

Screeching Bat // Stalking Vampire

Gravedigger

When Gravedigger enters the battlefield, you may return target creature card from your graveyard to your hand.

Black Cat

When Black Cat dies, target opponent discards a card at random.

Stolen Vitality

Target creature gets +3/+1 until end of turn. If it's your turn, that creature gains trample until end of turn. Otherwise, it gains first strike until end of turn.

Cold-Eyed Selkie

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
Whenever Cold-Eyed Selkie deals combat damage to a player, you may draw that many cards.

Fleshtaker

Whenever you sacrifice another creature, you gain 1 life and scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)
{1}, Sacrifice another creature: Fleshtaker gets +2/+2 until end of turn.

Zombie Apocalypse

Return all Zombie creature cards from your graveyard to the battlefield tapped, then destroy all Humans.

Buried Alive

Search your library for up to three creature cards, put them into your graveyard, then shuffle.

Demogorgon's Clutches

Target opponent discards two cards, mills two cards, and loses 2 life. (To mill a card, a player puts the top card of their library into their graveyard.)

Blinding Souleater

{W/P}, {T}: Tap target creature. ({W/P} can be paid with either {W} or 2 life.)

Force of Nature

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
At the beginning of your upkeep, Force of Nature deals 8 damage to you unless you pay {G}{G}{G}{G}.

Bubbling Cauldron

{1}, {T}, Sacrifice a creature: You gain 4 life.
{1}, {T}, Sacrifice a creature named Festering Newt: Each opponent loses 4 life. You gain life equal to the life lost this way.

Field Creeper

Headless Horseman

Angelic Purge

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

Silhouette

Choose target creature. If a spell or ability that targets that creature would cause a source to deal damage to that creature this turn, prevent that damage.

Frankenstein's Monster

As Frankenstein's Monster enters the battlefield, exile X creature cards from your graveyard. If you can't, put Frankenstein's Monster into its owner's graveyard instead of onto the battlefield. For each creature card exiled this way, Frankenstein's Monster enters the battlefield with a +2/+0, +1/+1, or +0/+2 counter on it.

Festering Newt

When Festering Newt dies, target creature an opponent controls gets -1/-1 until end of turn. That creature gets -4/-4 instead if you control a creature named Bogbrew Witch.

Spy Kit

Equipped creature gets +1/+1 and has all names of nonlegendary creature cards in addition to its name.
Equip {2}

All Hallow's Eve

Exile All Hallow's Eve with two scream counters on it.
At the beginning of your upkeep, if All Hallow's Eve is exiled with a scream counter on it, remove a scream counter from it. If there are no more scream counters on it, put it into your graveyard and each player returns all creature cards from their graveyard to the battlefield.

Join the Dance

Create two 1/1 white Human creature tokens.
Flashback {3}{G}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Dawn of the Dead

At the beginning of your upkeep, you lose 1 life.
At the beginning of your upkeep, you may return target creature card from your graveyard to the battlefield. That creature gains haste until end of turn. Exile it at the beginning of the next end step.

Hearthfire Hobgoblin

Stitcher Geralf

{2}{U}, {T}: Each player mills three cards. Exile up to two creature cards put into graveyards this way. Create an X/X blue Zombie creature token, where X is the total power of the cards exiled this way.

Fibrous Entangler

Vigilance
Fibrous Entangler must be blocked if able.
Fibrous Entangler can block an additional creature each combat.

Tangleclaw Werewolf

Tangleclaw Werewolf can block an additional creature each combat.
{6}{G}: Transform Tangleclaw Werewolf.

Tangleclaw Werewolf // Fibrous Entangler

Predator Ooze

Indestructible
Whenever Predator Ooze attacks, put a +1/+1 counter on it.
Whenever a creature dealt damage by Predator Ooze this turn dies, put a +1/+1 counter on Predator Ooze.

Crow of Dark Tidings

Flying
When Crow of Dark Tidings enters the battlefield or dies, mill two cards. (Put the top two cards of your library into your graveyard.)

Tombstone Stairwell

Cumulative upkeep {1}{B} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
At the beginning of each upkeep, if Tombstone Stairwell is on the battlefield, each player creates a 2/2 black Zombie creature token with haste named Tombspawn for each creature card in their graveyard.
At the beginning of each end step or when Tombstone Stairwell leaves the battlefield, destroy all tokens created with Tombstone Stairwell. They can't be regenerated.

Phyrexian Unlife

You don't lose the game for having 0 or less life.
As long as you have 0 or less life, all damage is dealt to you as though its source had infect. (Damage is dealt to you in the form of poison counters.)

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.

Masked Admirers

When Masked Admirers enters the battlefield, draw a card.
Whenever you cast a creature spell, you may pay {G}{G}. If you do, return Masked Admirers from your graveyard to your hand.

Homicidal Brute

At the beginning of your end step, if Homicidal Brute didn't attack this turn, tap Homicidal Brute, then transform it.

Civilized Scholar

{T}: Draw a card, then discard a card. If a creature card is discarded this way, untap Civilized Scholar, then transform it.

Civilized Scholar // Homicidal Brute

Greater Werewolf

At end of combat, put a -0/-2 counter on each creature blocking or blocked by Greater Werewolf.

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.

Blood Mist

At the beginning of combat on your turn, target creature you control gains double strike until end of turn.

Cemetery Gate

Defender (This creature can't attack.)
Protection from black

Season of the Witch

At the beginning of your upkeep, sacrifice Season of the Witch unless you pay 2 life.
At the beginning of the end step, destroy all untapped creatures that didn't attack this turn, except for creatures that couldn't attack.

Rooftop Storm

You may pay {0} rather than pay the mana cost for Zombie creature spells you cast.

Phantom Monster

Bogbrew Witch

{2}, {T}: Search your library for a card named Festering Newt or Bubbling Cauldron, put it onto the battlefield tapped, then shuffle.

Insectile Aberration

Delver of Secrets

At the beginning of your upkeep, look at the top card of your library. You may reveal that card. If an instant or sorcery card is revealed this way, transform Delver of Secrets.

Delver of Secrets // Insectile Aberration

Sengir Vampire

Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever a creature dealt damage by Sengir Vampire this turn dies, put a +1/+1 counter on Sengir Vampire.

Ghost Quarter

{T}: Add {C}.
{T}, Sacrifice Ghost Quarter: Destroy target land. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.