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

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.

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.)

When Burglar Rat enters the battlefield, each opponent discards a card.

{T}: Add {C}.

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

When Court of Ambition enters the battlefield, you become the monarch.

At the beginning of your upkeep, each opponent loses 3 life unless they discard a card. If you're the monarch, instead each opponent loses 6 life unless they discard two cards.

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.

Crypt of Agadeem enters the battlefield tapped.

{T}: Add {B}.

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

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.")

Flash

Whenever a creature you control dies, each opponent sacrifices a creature.

{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.

As Door of Destinies enters the battlefield, choose a creature type.

Whenever you cast a spell of the chosen type, put a charge counter on Door of Destinies.

Creatures you control of the chosen type get +1/+1 for each charge counter on Door of Destinies.

{T}: Add {C}.

{2}, {T}: Each player draws a card, then discards a card.

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.)

{2}{B}: Infected Vermin deals 1 damage to each creature and each player.

Threshold -- {3}{B}: Infected Vermin deals 3 damage to each creature and each player. Activate only if seven or more cards are in your graveyard.

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

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.

If Leyline of the Void is in your opening hand, you may begin the game with it on the battlefield.

If a card would be put into an opponent's graveyard from anywhere, exile it instead.

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

Equip {0}

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

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.

{T}: Add {C}.

{1}, {T}, Sacrifice Mind Stone: Draw a card.

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

{1}{B}: Exile target card from an opponent's graveyard. If no cards are in that graveyard, flip Nezumi Graverobber.

{4}{B}: Put target creature card from a graveyard onto the battlefield under your control.

{1}{B}, {T}: Target opponent discards a card. Then if that player has no cards in hand, flip Nezumi Shortfang.

At the beginning of each opponent's upkeep, that player loses 1 life for each card fewer than three in their hand.

{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.

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.

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.

Whenever an opponent casts a spell, that player loses 5 life unless they discard a card.

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.

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

Relentless Rats gets +1/+1 for each other creature on the battlefield named Relentless Rats.

A deck can have any number of cards named Relentless Rats.

Relentless Rats gets +1/+1 for each other creature on the battlefield named Relentless Rats.

A deck can have any number of cards named Relentless Rats.

Relentless Rats gets +1/+1 for each other creature on the battlefield named Relentless Rats.

A deck can have any number of cards named Relentless Rats.

Relentless Rats gets +1/+1 for each other creature on the battlefield named Relentless Rats.

A deck can have any number of cards named Relentless Rats.

Relentless Rats gets +1/+1 for each other creature on the battlefield named Relentless Rats.

A deck can have any number of cards named Relentless Rats.

Relentless Rats gets +1/+1 for each other creature on the battlefield named Relentless Rats.

A deck can have any number of cards named Relentless Rats.

Relentless Rats gets +1/+1 for each other creature on the battlefield named Relentless Rats.

A deck can have any number of cards named Relentless Rats.

Relentless Rats gets +1/+1 for each other creature on the battlefield named Relentless Rats.

A deck can have any number of cards named Relentless Rats.

Equipped creature gets +1/-1.

Whenever equipped creature dies, draw two cards.

Equip {1}

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

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.

{T}, Exile Surveyor's Scope: Search your library for up to X basic land cards, where X is the number of players who control at least two more lands than you. Put those cards onto the battlefield, then shuffle.

({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 {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

{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.)

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)

Equip {1}

Tangled Colony can't block.

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

You have no maximum hand size.

{T}: Add {C}.

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.

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

As Vanquisher's Banner enters the battlefield, 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.

Whenever an opponent discards a creature card, create a 2/2 black Zombie creature token.

Whenever an opponent discards a land card, add {B}{B}.

Whenever an opponent discards a noncreature, nonland card, draw a card.