Commander creatures you own have "Whenever an artifact or creature you control is put into a graveyard from the battlefield, each opponent loses 1 life."

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

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

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

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. {T}, Sacrifice this land: Target creature with power 2 or less can't be blocked this turn.

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

{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.

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.)

({T}: Add {B}.)

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

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

As Three Tree City enters, choose a creature type. {T}: Add {C}. {2}, {T}: Choose a color. Add an amount of mana of that color equal to the number of creatures you control of the chosen type.

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

{T}: Add {C}. {3}, {T}, Pay life equal to the number of colors in your commanders' color identity: Draw a card.

Whenever Ayara or another black creature you control enters, each opponent loses 1 life and you gain 1 life. {T}, Sacrifice another black creature: Draw a card.

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

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.

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.

Target player draws two cards and loses 2 life.

Equipped creature gets +1/-1. Whenever equipped creature dies, draw two cards. Equip {1}

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.

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.

{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.

Add {B}{B}{B}.

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.

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

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

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.

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

Ward {2} As this creature enters, choose a creature type. This creature is the chosen type in addition to its other types. If a triggered ability of another creature you control of the chosen type triggers, it triggers an additional time.

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.

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.)

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.)

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

Each player chooses a creature type. Each player returns all creature cards of a type chosen this way from their graveyard to the battlefield.

When this creature enters, each opponent discards a card.

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 this creature.

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

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

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