Jet Medallion

Black spells you cast cost {1} less to cast.

Burglar Rat

When Burglar Rat enters, each opponent discards a card.

Sol Ring

Ogre Slumlord

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

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Swamp

Profane Tutor

Suspend 2—{1}{B} (Rather than cast this card from your hand, pay {1}{B} and exile it with two time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)
Search your library for a card, put that card into your hand, then shuffle.

Nykthos, Shrine to Nyx

{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

Damnation

Destroy all creatures. They can't be regenerated.

Bojuka Bog

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

Throat Slitter

Ninjutsu {2}{B} ({2}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Throat Slitter deals combat damage to a player, destroy target nonblack creature that player controls.

Infernal Grasp

Destroy target creature. You lose 2 life.

Deadly Rollick

If you control a commander, you may cast this spell without paying its mana cost.
Exile target creature.

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Toxic Deluge

As an additional cost to cast this spell, pay X life.
All creatures get -X/-X until end of turn.

Whip of Erebos

Creatures you control have lifelink.
{2}{B}{B}, {T}: Return target creature card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step. If it would leave the battlefield, exile it instead of putting it anywhere else. Activate only as a sorcery.

Rat Colony

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

Liliana of the Dark Realms

+1: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.
−3: Target creature gets +X/+X or -X/-X until end of turn, where X is the number of Swamps you control.
−6: You get an emblem with "Swamps you control have '{T}: Add {B}{B}{B}{B}.'"

Path of Ancestry

Path of Ancestry enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Torment of Hailfire

Repeat the following process X times. Each opponent loses 3 life unless that player sacrifices a nonland permanent or discards a card.

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.

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 Pack Rat.

Gnawing Vermin

When Gnawing Vermin enters, target player mills two cards.
When Gnawing Vermin dies, target creature you don't control gets -1/-1 until end of turn.

Typhoid Rats

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Karumonix, the Rat King

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
Other Rats you control have toxic 1.
When Karumonix enters, look at the top five cards of your library. You may reveal any number of Rat cards from among them and put the revealed cards into your hand. Put the rest on the bottom of your library in a random order.

Throne of the God-Pharaoh

At the beginning of your end step, each opponent loses life equal to the number of tapped creatures you control.

Mutilate

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

Altar's Reap

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

Castle Locthwain

Castle Locthwain enters tapped unless you control a Swamp.
{T}: Add {B}.
{1}{B}{B}, {T}: Draw a card, then you lose life equal to the number of cards in your hand.

Swarm of Rats

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

Phyrexian Obliterator

Trample
Whenever a source deals damage to Phyrexian Obliterator, that source's controller sacrifices that many permanents.

Ink-Eyes, Servant of Oni

Ninjutsu {3}{B}{B} ({3}{B}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Ink-Eyes, Servant of Oni deals combat damage to a player, you may put target creature card from that player's graveyard onto the battlefield under your control.
{1}{B}: Regenerate Ink-Eyes.

Chittering Rats

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

Ravenous Rats

When Ravenous Rats enters, target opponent discards a card.

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.

Bog Rats

Species Specialist

As Species Specialist enters, choose a creature type.
Whenever a creature of the chosen type dies, you may draw a card.

Vampiric Tutor

Search your library for a card, then shuffle and put that card on top. You lose 2 life.

Arcane Signet

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

Septic Rats

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Whenever Septic Rats attacks, if defending player is poisoned, it gets +1/+1 until end of turn.

Zulaport Cutthroat

Whenever Zulaport Cutthroat or another creature you control dies, each opponent loses 1 life and you gain 1 life.

Gravepurge

Put any number of target creature cards from your graveyard on top of your library.
Draw a card.

Village Rites

Bad Moon

Dark Ritual

Ruin Rat

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

Adaptive Automaton

As Adaptive Automaton enters, choose a creature type.
Adaptive Automaton is the chosen type in addition to its other types.
Other creatures you control of the chosen type get +1/+1.

Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

Eldrazi Monument

Creatures you control get +1/+1 and have flying and indestructible.
At the beginning of your upkeep, sacrifice a creature. If you can't, sacrifice Eldrazi Monument.

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.

Crypt Rats

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

Gnat Miser

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

Sceptre of Eternal Glory

{T}: Add one mana of any color.
{T}: Add three mana of any one color. Activate only if you control three or more lands with the same name.

Nezumi Prowler

Ninjutsu {1}{B} ({1}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
When Nezumi Prowler enters, target creature you control gains deathtouch and lifelink until end of turn.

Force of Despair

If it's not your turn, you may exile a black card from your hand rather than pay this spell's mana cost.
Destroy all creatures that entered this turn.

Nezumi Bone-Reader

{B}, Sacrifice a creature: Target player discards a card. Activate only as a sorcery.

Nashi, Moon Sage's Scion

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 Nashi, Moon Sage's Scion deals combat damage to a player, exile the top card of each player's library. Until end of turn, you may play one of those cards. If you cast a spell this way, pay life equal to its mana value rather than paying its mana cost.

Doom Blade

Nezumi Bladeblesser

Nezumi Bladeblesser has deathtouch as long as you control an artifact.
Nezumi Bladeblesser has menace as long as you control an enchantment. (It can't be blocked except by two or more creatures.)

Ashcoat of the Shadow Swarm

Whenever Ashcoat of the Shadow Swarm attacks or blocks, other Rats you control get +X/+X until end of turn, where X is the number of Rats you control.
At the beginning of your end step, you may mill four cards. If you do, return up to two Rat creature cards from your graveyard to your hand. (To mill a card, put the top card of your library into your graveyard.)

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, each player gets a poison counter.

Echoing Return

Return target creature card and all other cards with the same name as that card from your graveyard to your hand.

Megrim

Whenever an opponent discards a card, Megrim deals 2 damage to that player.

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

Herald's Horn

As Herald's Horn enters, choose a creature type.
Creature spells you cast of the chosen type cost {1} less to cast.
At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.

Crippling Fear

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

Cabal Coffers

{2}, {T}: Add {B} for each Swamp you control.

Defile

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

Cut Down

Destroy target creature with total power and toughness 5 or less.

Stronghold Rats

Shadow (This creature can block or be blocked by only creatures with shadow.)
Whenever Stronghold Rats deals combat damage to a player, each player discards a card.

Cabal Stronghold

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

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.)

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.

Cavern of Souls

As Cavern of Souls enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

Demonic Tutor

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

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.)

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.