As Adaptive Automaton enters the battlefield, 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.

Create thirteen tapped 2/2 black Zombie creature tokens.

Flashback {7}{B}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

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.)

Sacrifice a creature: Add {C}{C}.

Whenever Ayara, First of Locthwain or another black creature enters the battlefield under your control, each opponent loses 1 life and you gain 1 life.

{T}, Sacrifice another black creature: Draw a card.

Black creatures get +1/+1.

At the beginning of your upkeep, you lose 1 life and create a 1/1 black Faerie Rogue creature token with flying.

At the beginning of your precombat main phase, choose one or more --

• Sell Contraband -- Create a Treasure token. You lose 1 life.

• Buy Information -- Draw a card. You lose 2 life.

• Hire a Mercenary -- Create a 3/2 colorless Shapeshifter creature token with changeling. You lose 3 life. (It has every creature type.)

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)

When Blightbelly Rat dies, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

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

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.

At the beginning of your end step, you may sacrifice an artifact, creature, enchantment, land, or planeswalker. If you do, each opponent may sacrifice a permanent that shares a card type with it. For each opponent who doesn't, that player loses 2 life and you draw a card.

Until end of turn, whenever a player taps a Swamp for mana, that player adds an additional {B}.

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

As Cavern of Souls enters the battlefield, 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.

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.

Equipped creature gets +3/+3 and has protection from each color that's not in your commander's color identity.

Equip commander {3}

Equip {5}

At the beginning of your upkeep, sacrifice Contamination unless you sacrifice a creature.

If a land is tapped for mana, it produces {B} instead of any other type and amount.

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}.

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

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

Add {B}{B}{B}{B}.

Destroy all creatures. They can't be regenerated.

Add {B}{B}{B}.

As an additional cost to cast this spell, sacrifice an artifact or creature.

Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

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

Exile target creature.

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

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

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

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.

Whenever you cast a creature spell, create X 1/1 black Thrull creature tokens, where X is that spell's mana value.

When you control seven or more Thrulls, sacrifice Endrek Sahr, Master Breeder.

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

Imprint -- When Extraplanar Lens enters the battlefield, you may exile target land you control.

Whenever a land with the same name as the exiled card is tapped for mana, its controller adds one mana of any type that land produced.

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

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

Whenever a creature you control dies, each other player sacrifices a creature.

When Gray Merchant of Asphodel enters the battlefield, 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.)

Each opponent loses 1 life for each creature you control.

Choose a creature type. Return up to two creature cards of that type from your graveyard to the battlefield. If this spell was foretold, return all creature cards of that type from your graveyard to the battlefield instead.

Foretell {5}{B}{B} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

As Herald's Horn enters the battlefield, 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.

Destroy target creature or planeswalker.

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.

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

Destroy target creature. You lose 2 life.

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

{T}, Sacrifice Jeweled Lotus: Add three mana of any one color. Spend this mana only to cast your commander.

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)

Other Rats you control have toxic 1.

When Karumonix enters the battlefield, 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.

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

+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}.'"

At the beginning of your upkeep, flip a coin. If you lose the flip, Mana Crypt deals 3 damage to you.

{T}: Add {C}{C}.

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.

You draw two cards and you lose 2 life.

{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.)

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

Rats you control have deathtouch.

Flash

You control your opponents while they're searching their libraries.

While an opponent is searching their library, they exile each card they find. You may play those cards for as long as they remain exiled, and you may spend mana as though it were mana of any color to cast them.

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.

Path of Ancestry enters the battlefield 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.)

At the beginning of your upkeep, you draw a card and you lose 1 life.

{1}{B}, Pay 2 life: Return target creature card from your graveyard to your hand.

{T}: Add {C}.

{T}, Sacrifice a creature: Add {B}{B}.

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.

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 Colony gets +1/+0 for each other Rat you control.

A deck can have any number of cards named Rat Colony.

Rat Colony gets +1/+0 for each other Rat you control.

A deck can have any number of cards named Rat Colony.

Rat Colony gets +1/+0 for each other Rat you control.

A deck can have any number of cards named Rat Colony.

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.

Put target creature card from a graveyard onto the battlefield under your control. You lose life equal to its mana value.

{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.

{1}: Look at the top three cards of your library, then put them back in any order.

{T}: Draw a card, then put Sensei's Divining Top on top of its owner's library.

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.

Deathtouch

Whenever you draw a card, you gain 2 life.

Whenever an opponent draws a card, they lose 2 life.

Equipped creature gets +1/-1.

Whenever equipped creature dies, draw two cards.

Equip {1}

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

{T}: Add {C}{C}.

As Species Specialist enters the battlefield, choose a creature type.

Whenever a creature of the chosen type dies, you may draw a card.

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

{T}: Add {C}.

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

If an opponent would gain life, that player loses that much life instead.

{T}: Add {B}.

Channel -- {3}{B}, Discard Takenuma, Abandoned Mire: Mill three cards, then return a creature or planeswalker card from your graveyard to your hand. This ability costs {1} less to activate for each legendary creature you control.

When The Meathook Massacre enters the battlefield, each creature gets -X/-X until end of turn.

Whenever a creature you control dies, each opponent loses 1 life.

Whenever a creature an opponent controls dies, you gain 1 life.

Equipped creature has "{2}, {T}: This creature deals 1 damage to any target" and "Whenever a creature dies, untap this creature."

Whenever a Shaman creature enters the battlefield, you may attach Thornbite Staff to it.

Equip {4}

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

As an additional cost to cast this spell, pay X life.

All creatures get -X/-X until end of turn.

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

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

As Urza's Incubator enters the battlefield, choose a creature type.

Creature spells of the chosen type cost {2} less to cast.

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

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

Draw two cards.

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.