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.

As Hall of Triumph enters the battlefield, choose a color. Creatures you control of the chosen color get +1/+1.

Equipped creature gets +3/+1. Whenever equipped creature dies, you may reveal cards from the top of your library until you reveal a creature card that shares a creature type with it. Put that card into your hand and the rest on the bottom of your library in a random order. Equip {1}

As Icon of Ancestry enters the battlefield, 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.

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.) Equip {1}

Equipped creature has "{2}, {T}: This creature deals 1 damage to any target" and "Whenever a creature dies, untap this creature." Whenever a Shaman creature enters the battlefield, you may attach Thornbite Staff to it. Equip {4}

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.

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.

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.

{2}{B}: Infected Vermin deals 1 damage to each creature and each player. Threshold — {3}{B}: Infected Vermin deals 3 damage to each creature and each player. Activate only if seven or more cards are in your graveyard.

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.

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 {1}{B} ({1}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.) Lifelink

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.)

{B}, Sacrifice a creature: Target player discards a card. Activate only as a sorcery.

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.

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.

Rat offering (You may cast this card any time you could cast an instant by sacrificing a Rat and paying the difference in mana costs between this and the sacrificed Rat. Mana cost includes color.) Whenever a permanent is put into an opponent's graveyard, that player loses 1 life.

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.)

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

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.)

{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.

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.

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.)

Whenever a creature you control deals combat damage to a player, that player discards a card.

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

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

Destroy target creature or planeswalker.

Destroy target creature. You lose 2 life.

Destroy target creature.

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.

{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.

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}.

Piranha Marsh enters the battlefield tapped. When Piranha Marsh enters the battlefield, target player loses 1 life. {T}: Add {B}.

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

({T}: Add {B}.)

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

Put target artifact or creature card from a graveyard onto the battlefield under your control. Shuffle Beacon of Unrest into its owner's library.

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.

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

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

Scry 2, then draw two cards. You lose 2 life.