When Contagion Clasp enters the battlefield, put a -1/-1 counter on target creature. {4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Equipped creature has defender and "{2}, {T}: Other creatures you control gain trample and get +X/+X until end of turn, where X is this creature's power." Equip {3}

Multikicker {2} (You may pay an additional {2} any number of times as you cast this spell.) Everflowing Chalice enters the battlefield with a charge counter on it for each time it was kicked. {T}: Add {C} for each charge counter on Everflowing Chalice.

Glistening Sphere enters the battlefield tapped. When Glistening Sphere enters the battlefield, proliferate. {T}: Add one mana of any color. Corrupted — {T}: Add three mana of any one color. Activate only if an opponent has three or more poison counters.

Equipped creature gets +2/+2 and has infect. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.) Whenever Grafted Exoskeleton becomes unattached from a permanent, sacrifice that permanent. Equip {2}

When Ichor Wellspring enters the battlefield or is put into a graveyard from the battlefield, draw a card.

{T}, Sacrifice Mishra's Bauble: Look at the top card of target player's library. Draw a card at the beginning of the next turn's upkeep.

When Mycosynth Wellspring enters the battlefield or is put into a graveyard from the battlefield, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.

{T}: Add one mana of any color. Corrupted — Whenever Phyrexian Atlas becomes tapped, each opponent who has three or more poison counters loses 1 life.

Equipped creature gets +0/+2 and has toxic 1. (Players dealt combat damage by equipped creature also get a poison counter.) Equip {1}

{T}: Add one mana of any color. At the beginning of your upkeep, put a night counter on Replicating Ring. Then if it has eight or more night counters on it, remove all of them and create eight colorless snow artifact tokens named Replicated Ring with "{T}: Add one mana of any color."

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

{T}, Sacrifice an artifact: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

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.)

Changeling (This card is every creature type.) As Bloodline Pretender enters the battlefield, choose a creature type. Whenever another creature of the chosen type enters the battlefield under your control, put a +1/+1 counter on Bloodline Pretender.

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

Changeling (This card is every creature type.) Changeling Outcast can't block and can't be blocked.

Corrupted — Sacrifice an artifact or creature: Draw a card. Activate only if an opponent has three or more poison counters and only once each turn.

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.

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

Changeling (This card is every creature type.) When Graveshifter enters the battlefield, you may return target creature card from your graveyard to your hand.

When Gulping Scraptrap enters the battlefield or dies, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

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.

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

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.

Deathtouch When Ruin Rat dies, exile target card from an opponent's graveyard.

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.

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.

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

Enchant creature Enchanted creature gets +1/+1. When enchanted creature dies, return that card to its owner's hand.

Enchant creature Enchanted creature has infect. At the beginning of your upkeep, put a -1/-1 counter on enchanted creature. When Glistening Oil is put into a graveyard from the battlefield, return Glistening Oil to its owner's hand.

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.)

Enchant creature you control Enchanted creature has toxic 2. (Players dealt combat damage by it also get two poison counters.) When enchanted creature dies, return that card to the battlefield under your control.

When Oubliette enters the battlefield, target creature phases out until Oubliette leaves the battlefield. Tap that creature as it phases in this way. (Auras and Equipment phase out with it. While permanents are phased out, they're treated as though they don't exist.)

At the beginning of your upkeep, if you have four or more creature cards in your graveyard, you may return target creature card from your graveyard to your hand.

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

Enchant creature When Strands of Undeath enters the battlefield, target player discards two cards. {B}: Regenerate enchanted creature.

At the beginning of your upkeep, you may put a verse counter on Vile Requiem. {1}{B}, Sacrifice Vile Requiem: Destroy up to X target nonblack creatures, where X is the number of verse counters on Vile Requiem. They can't be regenerated.

Exile target creature if it has mana value 3 or less. Corrupted — Exile that creature instead if its controller has three or more poison counters.

Add {B}{B}{B}.

Until end of turn, target creature gains "When this creature dies, return it to the battlefield tapped under its owner's control with a +1/+1 counter on it."

Target creature gains deathtouch and indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Choose one — • Each opponent sacrifices a nontoken creature. • Each opponent sacrifices a creature token. • Each opponent sacrifices a planeswalker.

Until end of turn, target creature gets +2/+0 and gains "When this creature dies, return it to the battlefield tapped under its owner's control."

Tendrils of Corruption deals X damage to target creature and you gain X life, where X is the number of Swamps you control.

Until end of turn, target creature gains "When this creature dies, return it to the battlefield tapped under its owner's control with a +1/+1 counter on it."

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

{T}: Add {C}. {3}, {T}: Target creature with power 3 or less can't be blocked this turn.

{T}: Add {C}. {2}, {T}, Sacrifice Demolition Field: Destroy target nonbasic land an opponent controls. That land's controller may search their library for a basic land card, put it onto the battlefield, then shuffle. You may search your library for a basic land card, put it onto the battlefield, then shuffle.

{T}: Add {C}. {2}, {T}, Sacrifice Field of Ruin: Destroy target nonbasic land an opponent controls. Each player searches their library for a basic land card, puts it onto the battlefield, then shuffles.

Gemstone Mine enters the battlefield with three mining counters on it. {T}, Remove a mining counter from Gemstone Mine: Add one mana of any color. If there are no mining counters on Gemstone Mine, sacrifice it.

{T}: Add {C}. {3}, {T}, Sacrifice Haunted Fengraf: Return a creature card at random from your graveyard to your hand.

{T}: Add {C}. {T}, Sacrifice a creature: You gain 1 life.

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.)

Polluted Mire enters the battlefield tapped. {T}: Add {B}. Cycling {2} ({2}, Discard this card: Draw a card.)

{T}: Add {C}. {4}, {T}: Target creature can't be blocked this turn.

({T}: Add {B}.)

The Dross Pits enters the battlefield tapped. {T}: Add {B}. {1}{B}, {T}, Sacrifice The Dross Pits: Draw a card.

As an additional cost to cast this spell, pay {4} or sacrifice an artifact or creature. Destroy target creature or planeswalker.

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

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.)

As an additional cost to cast this spell, sacrifice a creature or pay {3}{B}. Exile target creature or planeswalker.

Put two +1/+1 counters on target creature. It gains lifelink until end of turn.

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

Target creature gets -3/-3 until end of turn. Cycling {2} ({2}, Discard this card: Draw a card.) Madness {3}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

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

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.

Return target creature card with mana value 3 or less from your graveyard to the battlefield. Cycling {2} ({2}, Discard this card: Draw a card.)