{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.

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

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

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.)

Bog Rats can't be blocked by Walls.

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.

When Chittering Rats enters the battlefield, target opponent puts a card from their hand on top of their library.

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.

When Drainpipe Vermin dies, you may pay {B}. If you do, target player discards a card.

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

When Gnawing Vermin enters the battlefield, target player mills two cards. When Gnawing Vermin dies, target creature you don't control gets -1/-1 until end of turn.

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.

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.

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, Moon Sage's Scion 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.

Nezumi Bladeblesser has deathtouch as long as you control an artifact. Nezumi Bladeblesser has menace as long as you control an enchantment. (It can't be blocked except by two or more creatures.)

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

When Nezumi Informant enters the battlefield, each opponent discards a card.

Ninjutsu {1}{B} ({1}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.) When Nezumi Prowler enters the battlefield, target creature you control gains deathtouch and lifelink until end of turn.

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.

Pestilence Rats's power is equal to the number of other Rats on the battlefield. (For example, as long as there are two other Rats on the battlefield, Pestilence Rats's power and toughness are 2/3.)

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.)

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.) At the beginning of your upkeep, you may search your library for a Rat card, reveal it, put it into your hand, then shuffle.

When Ravenous Rats enters the battlefield, target opponent discards a card.

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

When Rotting Rats enters the battlefield, each player discards a card. Unearth {1}{B} ({1}{B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

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

{T}: Exile the top card of target player's library. If it's a land card, you gain 1 life. Landfall — Whenever a land enters the battlefield under your control, you may untap Scrib Nibblers.

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.

{3}{B}{B}: Monstrosity 3. (If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.) As long as Sinuous Vermin is monstrous, it has menace. (It can't be blocked except by two or more creatures.)

Ninjutsu {B} ({B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.) Whenever Skullsnatcher deals combat damage to a player, exile up to two target cards from that player's graveyard.

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

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.

Swarm of Rats's power is equal to the number of Rats you control.

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

Black creatures get +1/+1.

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.

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

Add {B}{B}{B}.

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.")

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

Destroy target nonartifact creature.

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

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.

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

Bojuka Bog enters the battlefield tapped. When Bojuka Bog enters the battlefield, exile target player's graveyard. {T}: Add {B}.

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

Mortuary Mire enters the battlefield tapped. When Mortuary Mire enters the battlefield, you may put target creature card from your graveyard on top of your library. {T}: Add {B}.

Myriad Landscape enters the battlefield tapped. {T}: Add {C}. {2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

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.)

{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.

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.)

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

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

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

Target player draws two cards and loses 2 life.

Whenever Ashcoat of the Shadow Swarm 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 Ayara, First of Locthwain or another black creature enters the battlefield under your control, each opponent loses 1 life and you gain 1 life. {T}, Sacrifice another black creature: Draw a card.

Ninjutsu {3}{B}{B} ({3}{B}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.) Whenever Ink-Eyes, Servant of Oni deals combat damage to a player, you may put target creature card from that player's graveyard onto the battlefield under your control. {1}{B}: Regenerate Ink-Eyes.

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.

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.

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