Fellwar Stone

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

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.

Arcane Signet

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

Magus of the Coffers

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

Burnished Hart

{3}, Sacrifice this creature: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

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}.'"

Academy Manufactor

If you would create a Clue, Food, or Treasure token, instead create one of each.

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.

Crypt Rats

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

Gray Merchant of Asphodel

When this creature enters, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

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.

Insatiable Frugivore

When this creature enters, create a Food token, then you may exile three cards from your graveyard. If you do, repeat this process.
{3}{B}, Sacrifice X Foods: Creatures you control get +X/+0 and gain menace until end of turn.

Vampire Nighthawk

Flying
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

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.

Demonic Tutor

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

Nirkana Revenant

Whenever you tap a Swamp for mana, add an additional {B}.
{B}: This creature gets +1/+1 until end of turn.

Exsanguinate

Each opponent loses X life. You gain life equal to the life lost this way.

Royal Assassin

Clue

Twisted Sewer-Witch

When this creature enters, create a 1/1 black Rat creature token with "This creature can't block." Then for each Rat you control, create a Wicked Role token attached to that Rat. (If you control another Role on it, put that one into the graveyard. Enchanted creature gets +1/+1. When this token is put into a graveyard, each opponent loses 1 life.)

Experimental Confectioner

When this creature enters, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")
Whenever you sacrifice a Food, create a 1/1 black Rat creature token with "This token can't block."

Scavenger's Talent

(Gain the next level as a sorcery to add its ability.)
Whenever one or more creatures you control die, create a Food token. This ability triggers only once each turn.
{1}{B}: Level 2
Whenever you sacrifice a permanent, target player mills two cards.
{2}{B}: Level 3
At the beginning of your end step, you may sacrifice three other nonland permanents. If you do, return a creature card from your graveyard to the battlefield with a finality counter on it.

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."

Bojuka Bog

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

Insatiable Avarice

Spree (Choose one or more additional costs.)
+ {2} — Search your library for a card, then shuffle and put that card on top.
+ {B}{B} — Target player draws three cards and loses 3 life.

Mirkwood Bats

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

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 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.

Crypt Ghast

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
Whenever you tap a Swamp for mana, add an additional {B}.

Sol Ring

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.

Sign in Blood

Target player draws two cards and loses 2 life.

Corrupted Conviction

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

Food

{2}, {T}, Sacrifice this token: You gain 3 life.

Gruesome Fate

Each opponent loses 1 life for each creature you control.

Swarm of Rats

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

Mudflat Village

{T}: Add {C}.
{T}: Add {B}. Spend this mana only to cast a creature spell.
{1}{B}, {T}, Sacrifice this land: Return target Bat, Lizard, Rat, or Squirrel card from your graveyard to your hand.

Blood Artist

Whenever this creature or another creature dies, target player loses 1 life and you gain 1 life.

Infected Vermin

{2}{B}: This creature deals 1 damage to each creature and each player.
Threshold — {3}{B}: This creature deals 3 damage to each creature and each player. Activate only if there are seven or more cards in your graveyard.

Path of Ancestry

This land 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.)

Ormendahl, Profane Prince

Westvale Abbey

{T}: Add {C}.
{5}, {T}, Pay 1 life: Create a 1/1 white and black Human Cleric creature token.
{5}, {T}, Sacrifice five creatures: Transform this land, then untap it.

Westvale Abbey // Ormendahl, Profane Prince

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

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."

Fabled Passage

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Then if you control four or more lands, untap that land.

Village Rites

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.)

Expedition Map

{2}, {T}, Sacrifice this artifact: Search your library for a land card, reveal it, put it into your hand, then shuffle.

Leechridden Swamp

({T}: Add {B}.)
This land enters tapped.
{B}, {T}: Each opponent loses 1 life. Activate only if you control two or more black permanents.

Murder

Dark Ritual

Cabal Coffers

Jet Medallion

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

Cunning Rhetoric

Whenever an opponent attacks you and/or one or more planeswalkers you control, exile the top card of that player's library. You may play that card for as long as it remains exiled, and you may spend mana as though it were mana of any color to cast it.

Urborg, Tomb of Yawgmoth

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

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.

Typhoid Rats

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

Ogre Slumlord

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

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.)

Treasure

{T}, Sacrifice this token: Add one mana of any color.

Plague Wind

Destroy all creatures you don't control. They can't be regenerated.

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.

Swamp

Go for the Throat

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 this creature deals combat damage to a player, destroy target nonblack creature that player controls.

Toxic Deluge

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

Altar's Reap

Cabal Stronghold

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

Victimize

Choose two target creature cards in your graveyard. Sacrifice a creature. If you do, return the chosen cards to the battlefield tapped.

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.

Cursed

Enchant creature
Enchanted creature has base power and toughness 1/1.

Wicked

Enchant creature
Enchanted creature gets +1/+1.
When this Aura is put into a graveyard from the battlefield, each opponent loses 1 life.

Wicked // Cursed

Hecatomb

When this enchantment enters, sacrifice this enchantment unless you sacrifice four creatures.
Tap an untapped Swamp you control: This enchantment deals 1 damage to any target.

Akroma's Memorial

Creatures you control have flying, first strike, vigilance, trample, haste, and protection from black and from red.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Torment of Hailfire

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

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.

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.

Thought Vessel

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

Dark Deal

Each player discards all the cards in their hand, then draws that many cards minus one.

Tragic Fall

Target creature gets -3/-3 until end of turn.
Hellbent — That creature gets -13/-13 until end of turn instead if you have no cards in hand.

Rat Colony

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