You may look at the top card of your library any time. You may play lands and cast spells from the top of your library. If you cast a spell this way, pay life equal to its mana value rather than pay its mana cost. {T}, Sacrifice ten nonland permanents: Each opponent loses 10 life.

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 Herald's Horn enters the battlefield, 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.

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

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.

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.

Whenever Diseased Vermin deals combat damage to a player, put an infection counter on it. At the beginning of your upkeep, Diseased Vermin deals X damage to target opponent previously dealt damage by it, where X is the number of infection counters on it.

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.

When Gray Merchant of Asphodel enters the battlefield, 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.)

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.

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

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.

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

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.

Bushido 1 (Whenever this creature blocks or becomes blocked, it gets +1/+1 until end of turn.)

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

When Ossuary Rats enters the battlefield, it deals X damage to target creature or planeswalker an opponent controls, where X is the number of creature cards in your graveyard.

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.)

Relentless Rats gets +1/+1 for each other creature on the battlefield named Relentless Rats. A deck can have any number of cards named Relentless Rats.

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.

{B}, Pay 1 life: Sewer Rats gets +1/+0 until end of turn. Activate no more than three times each 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.

Whenever another creature dies, or a creature card is put into a graveyard from anywhere other than the battlefield, or a creature card leaves your graveyard, Syr Konrad, the Grim deals 1 damage to each opponent. {1}{B}: Each player mills a card. (They each put the top card of their library into their graveyard.)

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

Trample When Wave of Rats dies, if it dealt combat damage to a player this turn, return it to the battlefield under its owner's control. Blitz {4}{B} (If you cast this spell for its blitz cost, it gains haste and "When this creature dies, draw a card." Sacrifice it at the beginning of the next end step.)

Whenever a creature dies, put a charge counter on Black Market. At the beginning of your precombat main phase, add {B} for each charge counter on Black Market.

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.)

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

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

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

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

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.")

Return X target creature cards from your graveyard to your hand.

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

Destroy target nonblack creature.

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

Put any number of target creature cards from your graveyard on top of your library. Draw a card.

Destroy target creature. You lose 2 life.

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.) Until end of turn, creatures target player controls lose all abilities and have base power and toughness 0/2.

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.

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

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

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

Crypt of Agadeem enters the battlefield tapped. {T}: Add {B}. {2}, {T}: Add {B} for each black creature card in your graveyard.

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

({T}: Add {B}.)

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.

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.

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.

You draw two cards and you lose 2 life.

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.

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

Target player draws two cards and loses 2 life.

Reveal the top card of your library and put that card into your hand. You lose life equal to its mana value. You may repeat this process any number of times.

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.)

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

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.) Whenever you tap a Swamp for mana, add an additional {B}.

Whenever a creature you control dies, each other player sacrifices a creature.

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.

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 {2}{B} ({2}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.) Whenever Throat Slitter deals combat damage to a player, destroy target nonblack creature that player controls.

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