Crypt Rats

{X}: This creature deals X damage to each creature and each player. Spend only black mana on X.

Ayara, First of Locthwain

Whenever Ayara or another black creature you control enters, each opponent loses 1 life and you gain 1 life.
{T}, Sacrifice another black creature: Draw a card.

Charcoal Diamond

This artifact enters tapped.
{T}: Add {B}.

Epic Downfall

Exile target creature with mana value 3 or greater.

Defile

Target creature gets -1/-1 until end of turn for each Swamp you control.

Persistent Marshstalker

This creature gets +1/+0 for each other Rat you control.
Threshold — Whenever you attack with one or more Rats, if seven or more cards are in your graveyard, you may pay {2}{B}. If you do, return this card from your graveyard to the battlefield tapped and attacking.

Swarmyard

{T}: Add {C}.
{T}: Regenerate target Insect, Rat, Spider, or Squirrel. (The next time it would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Tangled Colony

This creature can't block.
When this creature dies, create X 1/1 black Rat creature tokens with "This token can't block," where X is the amount of damage dealt to it this turn.

Patchwork Banner

As this artifact enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
{T}: Add one mana of any color.

Ruin Rat

Deathtouch
When this creature dies, exile target card from an opponent's graveyard.

Crypt of Agadeem

This land enters tapped.
{T}: Add {B}.
{2}, {T}: Add {B} for each black creature card in your graveyard.

Swamp

Relentless Rats

This creature gets +1/+1 for each other creature on the battlefield named Relentless Rats.
A deck can have any number of cards named Relentless Rats.

Rat Colony

This creature gets +1/+0 for each other Rat you control.
A deck can have any number of cards named Rat Colony.

Murder

Mikaeus, the Unhallowed

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
Whenever a Human deals damage to you, destroy it.
Other non-Human creatures you control get +1/+1 and have undying. (When a creature with undying dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Icon of Ancestry

As this artifact enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
{3}, {T}: Look at the top three cards of your library. You may reveal a creature card of the chosen type from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Ogre Slumlord

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

Kindred Dominance

Choose a creature type. Destroy all creatures that aren't of the chosen type.

Valley Rotcaller

Menace
Whenever this creature attacks, each opponent loses X life and you gain X life, where X is the number of other Squirrels, Bats, Lizards, and Rats you control.

Rancid Rats

Skulk (This creature can't be blocked by creatures with greater power.)
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Rat Out

Up to one target creature gets -1/-1 until end of turn. You create a 1/1 black Rat creature token with "This token can't block."

Pestilence Rats

Pestilence Rats's power is equal to the number of other Rats on the battlefield. (For example, as long as there are two other Rats on the battlefield, Pestilence Rats's power and toughness are 2/3.)

Vanquisher's Banner

As this artifact enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
Whenever you cast a creature spell of the chosen type, draw a card.

Death Pit Offering

When this enchantment enters, sacrifice all creatures you control.
Creatures you control get +2/+2.

Village Rites

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

Pack Rat

Pack Rat's power and toughness are each equal to the number of Rats you control.
{2}{B}, Discard a card: Create a token that's a copy of this creature.

Patriarch's Bidding

Each player chooses a creature type. Each player returns all creature cards of a type chosen this way from their graveyard to the battlefield.

Burglar Rat

When this creature enters, each opponent discards a card.

Heraldic Banner

As this artifact enters, choose a color.
Creatures you control of the chosen color get +1/+0.
{T}: Add one mana of the chosen color.

Hall of Triumph

As Hall of Triumph enters, choose a color.
Creatures you control of the chosen color get +1/+1.

Wave of Rats

Trample
When this creature dies, if it dealt combat damage to a player this turn, return it to the battlefield under its owner's control.
Blitz {4}{B} (If you cast this spell for its blitz cost, it gains haste and "When this creature dies, draw a card." Sacrifice it at the beginning of the next end step.)

Black Market

Whenever a creature dies, put a charge counter on this enchantment.
At the beginning of your first main phase, add {B} for each charge counter on this enchantment.

Vampiric Rites

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

Witch's Cottage

({T}: Add {B}.)
This land enters tapped unless you control three or more other Swamps.
When this land enters untapped, you may put target creature card from your graveyard on top of your library.

Lord Skitter, Sewer King

Whenever another Rat you control enters, exile up to one target card from an opponent's graveyard.
At the beginning of combat on your turn, create a 1/1 black Rat creature token with "This token can't block."

Lord Skitter's Butcher

When this creature enters, choose one —
• Create a 1/1 black Rat creature token with "This token can't block."
• You may sacrifice another creature. If you do, scry 2, then draw a card.
• Creatures you control gain menace until end of turn.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Mirkwood Bats

Flying
Whenever you create or sacrifice a token, each opponent loses 1 life.

Ossuary Rats

When this creature enters, it deals X damage to target creature or planeswalker an opponent controls, where X is the number of creature cards in your graveyard.

Swarm of Rats

Swarm of Rats's power is equal to the number of Rats you control.

Marrow-Gnawer

All Rats have fear.
{T}, Sacrifice a Rat: Create X 1/1 black Rat creature tokens, where X is the number of Rats you control.

Gruesome Fate

Each opponent loses 1 life for each creature you control.

Ratcatcher

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
At the beginning of your upkeep, you may search your library for a Rat card, reveal it, put it into your hand, then shuffle.

Go for the Throat

Piper of the Swarm

Rats you control have menace.
{1}{B}, {T}: Create a 1/1 black Rat creature token.
{2}{B}{B}, {T}, Sacrifice three Rats: Gain control of target creature.

Hero's Downfall

Bad Moon

Bitter Triumph

As an additional cost to cast this spell, discard a card or pay 3 life.
Destroy target creature or planeswalker.

Bojuka Bog

This land enters tapped.
When this land enters, exile target player's graveyard.
{T}: Add {B}.

Crippling Fear

Choose a creature type. Creatures that aren't of the chosen type get -3/-3 until end of turn.

Voracious Vermin

When this creature enters, create a 1/1 black Rat creature token with "This token can't block."
Whenever another creature you control dies, put a +1/+1 counter on this creature.

Foul-Tongue Shriek

Target opponent loses 1 life for each attacking creature you control. You gain that much life.

Bontu's Monument

Black creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, each opponent loses 1 life and you gain 1 life.