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

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.

Tap two untapped creatures you control: You may put a creature card from your hand that shares a creature type with each creature tapped this way onto the battlefield.

As this artifact enters, choose a creature type. Whenever you cast a spell of the chosen type, put a charge counter on this artifact. Creatures you control of the chosen type get +1/+1 for each charge counter on this artifact.

As this artifact 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.

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.

As this artifact enters, choose a creature type. Creatures you control of the chosen type get +1/+1. {3}, {T}: Look at the top three cards of your library. You may reveal a creature card of the chosen type from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

{T}: Add {C}. {1}, {T}, Sacrifice this artifact: Draw a card.

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.) As this artifact enters, choose a creature type. Creatures you control of the chosen type get +2/+2.

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

Whenever Ashcoat 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.)

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

Changeling (This card is every creature type.) As this creature enters, choose a creature type. Whenever another creature you control of the chosen type enters, put a +1/+1 counter on this creature.

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.

As this creature enters, choose a creature type. This creature is the chosen type in addition to its other types. Each other creature you control of the chosen type enters with an additional +1/+1 counter on it.

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.

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

When this enchantment enters, create a 1/1 white Human Soldier creature token. Whenever a creature you control dies, each opponent loses 1 life and you gain 1 life.

At the beginning of your upkeep, sacrifice this enchantment unless you sacrifice a creature. If a land is tapped for mana, it produces {B} instead of any other type and amount.

Flash Whenever a creature you control dies, each opponent sacrifices a creature of their choice.

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

Whenever a player casts a spell, counter it unless that player pays {3}.

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

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

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

{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.)

({T}: Add {B}.)

Return up to three target creature cards of the creature type of your choice from your graveyard to your hand.

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

As an additional cost to cast this spell, sacrifice a creature. Search your library for a card, put that card into your hand, then shuffle.

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

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.

Target opponent reveals their hand. You choose a creature card from it. That player discards that card. Scry 1.

Destroy all creatures you don't control and all planeswalkers you don't control.

Target player reveals their hand. You choose a nonland card from it with mana value 3 or less. That player discards that card.

Target player reveals their hand. You choose a nonland card from it. That player discards that card. You lose 2 life.

{2}, {T}, Sacrifice a creature: Search your library for a creature card that shares a creature type with the sacrificed creature and has mana value equal to 1 plus that creature's mana value. Put that card onto the battlefield, then shuffle. Activate only as a sorcery.