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.

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 and create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

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.

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.

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

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.

Exile target nonland card from your graveyard. Search your library for any number of cards with the same name as that card, reveal them, put them into your hand, then shuffle.

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

As Vanquisher's Banner enters the battlefield, choose a creature type. Creatures you control of the chosen type get +1/+1. Whenever you cast a creature spell of the chosen type, draw a card.

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.) Other Rats you control have toxic 1. When Karumonix enters the battlefield, look at the top five cards of your library. You may reveal any number of Rat cards from among them and put the revealed cards into your hand. Put the rest on the bottom of your library in a random order.

Flying Whenever you create or sacrifice a token, each opponent loses 1 life.

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.

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}

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

Choose a creature type. Return up to two creature cards of that type from your graveyard to the battlefield. If this spell was foretold, return all creature cards of that type from your graveyard to the battlefield instead. Foretell {5}{B}{B} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

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.

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

Put target creature card from a graveyard onto the battlefield under your control. You lose life equal to its mana value.

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.)

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

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

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.

Add {B}{B}{B}.

{T}: Add one mana of any color. {1}, {T}: Untap target legendary creature you control.

As an additional cost to cast this spell, sacrifice a creature or discard a card. Destroy target creature or planeswalker.

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

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

Exile target creature or planeswalker. You gain life equal to the number of counters on it.

Destroy all creatures you don't control and all planeswalkers you don't control.

Each creature gets +1/+1 for each other creature on the battlefield that shares at least one creature type with it. (For example, if two Goblin Warriors and a Goblin Shaman are on the battlefield, each gets +2/+2.)

Whenever another Rat enters the battlefield under your control, exile up to one target card from an opponent's graveyard. At the beginning of combat on your turn, create a 1/1 black Rat creature token with "This creature can't block."

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.

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.

Equipped creature gets +1/+1 for each other creature you control that shares a creature type with it. Equip {2}

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

Castle Locthwain enters the battlefield tapped unless you control a Swamp. {T}: Add {B}. {1}{B}{B}, {T}: Draw a card, then you lose life equal to the number of cards in your hand.

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

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.)

Corrupt deals damage to any target equal to the number of Swamps you control. You gain life equal to the damage dealt this way.

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

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.)

Equipped creature has nonbasic landwalk. (It can't be blocked as long as defending player controls a nonbasic land.) Equip {2}

Each land is a Swamp in addition to its other land types.

When Voracious Vermin enters the battlefield, create a 1/1 black Rat creature token with "This creature can't block." Whenever another creature you control dies, put a +1/+1 counter on Voracious Vermin.