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

{T}: Add {C}. {3}, {T}: Add {B} for each basic 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 {C}. {T}, Sacrifice a creature: Add {B}{B}.

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

({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.)

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 one mana of any color in your commander's color identity.

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

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

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

Choose a creature type. Creatures that aren't of the chosen type get -3/-3 until end of turn.

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

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.

Target creature gets -4/-4 until end of turn. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

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

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

Each opponent loses 1 life for each creature you control.

You draw two cards and you lose 2 life. Each opponent gets a poison counter.

Each player exiles all creature cards from their graveyard, then sacrifices all creatures they control, then puts all cards they exiled this way onto the battlefield.

Choose a creature type. Target player draws X cards and loses X life, where X is the number of creatures they control of the chosen type.

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

Each opponent gets a poison counter. Then each creature your opponents control gets -1/-1 until end of turn for each poison counter its controller has.

Starting with you, each player may pay any amount of life. Repeat this process until no one pays life. Each player creates a 1/1 black Rat creature token for each 1 life they paid this way.

Until end of turn, creatures you control gain menace and "Whenever this creature deals combat damage to a player, exile the top card of that player's library face down. You may look at and 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 that spell."

Create a tapped 1/1 black Rat creature token for each creature card in your graveyard. Flashback {2}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Create two 1/1 green Squirrel creature tokens. Then each creature that isn't an Insect, Rat, Spider, or Squirrel gets -1/-1 until end of turn for each creature you control that's an Insect, Rat, Spider, or Squirrel.

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

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.)

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

As this creature enters, choose a creature type. Whenever a creature of the chosen type dies, you may draw a card.

As this enchantment enters, choose a creature type. Creatures of the chosen type have fear. (They can't be blocked except by artifact creatures and/or black creatures.)

Commander creatures you own have "Whenever this creature becomes tapped, it and other creatures you control that share a creature type with it each get +2/+0 and gain undying until end of turn." (When a creature with undying dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Add {B}{B}{B}. Threshold — Add {B}{B}{B}{B}{B} instead if seven or more cards are in your graveyard.

Add {B}{B}{B}.

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

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

Put a -1/-1 counter on target creature, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

As an additional cost to cast this spell, you may sacrifice one or more creatures. When you do, copy this spell for each creature sacrificed this way. You draw a card and you lose 1 life.

Target creature gets +1/+0 and gains infect until end of turn. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Target creature gets -1/-1 until end of turn. Morbid — That creature gets -13/-13 until end of turn instead if a creature died this turn.

Put a -1/-1 counter on target creature. When that creature dies this turn, its controller gets a poison counter.

Each opponent sacrifices a creature or planeswalker of their choice and gets a poison counter.