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 the battlefield, each player gets a poison counter.

Coat of Arms

Each creature gets +1/+1 for each other creature on the battlefield that shares at least one creature type with it. (For example, if two Goblin Warriors and a Goblin Shaman are on the battlefield, each gets +2/+2.)

Diseased Vermin

Whenever Diseased Vermin deals combat damage to a player, put an infection counter on it.
At the beginning of your upkeep, Diseased Vermin deals X damage to target opponent previously dealt damage by it, where X is the number of infection counters on it.

Disease Carriers

When Disease Carriers dies, target creature gets -2/-2 until end of turn.

Dirty Wererat

{B}, Discard a card: Regenerate Dirty Wererat.
Threshold — As long as seven or more cards are in your graveyard, Dirty Wererat gets +2/+2 and can't block.

Chittering Rats

When Chittering Rats enters the battlefield, target opponent puts a card from their hand on top of their library.

Skull of Ramos

{T}: Add {B}.
Sacrifice Skull of Ramos: Add {B}.

Razortooth Rats

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)

Bojuka Bog

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

Charcoal Diamond

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

Locust Miser

Each opponent's maximum hand size is reduced by two.

Rats of Rath

{B}: Destroy target artifact, creature, or land you control.

Earsplitting Rats

When Earsplitting Rats enters the battlefield, each player discards a card.
Discard a card: Regenerate Earsplitting Rats.

Skullsnatcher

Ninjutsu {B} ({B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Skullsnatcher deals combat damage to a player, exile up to two target cards from that player's graveyard.

Syphon Mind

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

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.

Bog Rats

Nezumi Cutthroat

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Nezumi Cutthroat can't block.

Thran Dynamo

Worn Powerstone

Worn Powerstone enters the battlefield tapped.
{T}: Add {C}{C}.

Sewer Rats

{B}, Pay 1 life: Sewer Rats gets +1/+0 until end of turn. Activate no more than three times each turn.

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.

Okiba-Gang Shinobi

Ninjutsu {3}{B} ({3}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Okiba-Gang Shinobi deals combat damage to a player, that player discards two cards.

Sol Ring

Chittering Witch

When Chittering Witch enters the battlefield, create a number of 1/1 black Rat creature tokens equal to the number of opponents you have.
{1}{B}, Sacrifice a creature: Target creature gets -2/-2 until end of turn.

Vampiric Link

Enchant creature
Whenever enchanted creature deals damage, you gain that much life.

Heraldic Banner

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

Graveshifter

Changeling (This card is every creature type.)
When Graveshifter enters the battlefield, you may return target creature card from your graveyard to your hand.

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.

Carrion Rats

Whenever Carrion Rats attacks or blocks, any player may exile a card from their graveyard. If a player does, Carrion Rats assigns no combat damage this turn.

Ravenous Rats

When Ravenous Rats enters the battlefield, target opponent discards a card.

Swarm of Rats

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

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Murder

Everflowing Chalice

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

Defile

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

Swamp

Cabal Stronghold

{T}: Add {C}.
{3}, {T}: Add {B} for each basic Swamp you control.

Crypt Rats

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

Black Market

Whenever a creature dies, put a charge counter on Black Market.
At the beginning of your precombat main phase, add {B} for each charge counter on Black Market.

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.)

Ruin Rat

Deathtouch
When Ruin Rat dies, exile target card from an opponent's graveyard.

Dark Ritual

Ogre Slumlord

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

Coldsteel Heart

Coldsteel Heart enters the battlefield tapped.
As Coldsteel Heart enters the battlefield, choose a color.
{T}: Add one mana of the chosen color.

Unhallowed Pact

Enchant creature
When enchanted creature dies, return that card to the battlefield under your control.

Foul-Tongue Shriek

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

Doom Blade

Return from Extinction

Choose one —
• Return target creature card from your graveyard to your hand.
• Return two target creature cards that share a creature type from your graveyard to your hand.

Hall of Triumph

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

Diabolic Tutor

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

Sign in Blood

Target player draws two cards and loses 2 life.

Lab Rats

Buyback {4} (You may pay an additional {4} as you cast this spell. If you do, put this card into your hand as it resolves.)
Create a 1/1 black Rat creature token.

Staff of the Death Magus

Whenever you cast a black spell or a Swamp enters the battlefield under your control, you gain 1 life.

Kuro's Taken

Bushido 1 (Whenever this creature blocks or becomes blocked, it gets +1/+1 until end of turn.)
{1}{B}: Regenerate Kuro's Taken.

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.)