Return from your graveyard to the battlefield any number of target creature cards that each have a different mana value X or less.

As Agadeem, the Undercrypt enters the battlefield, you may pay 3 life. If you don't, it enters the battlefield tapped.

{T}: Add {B}.

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.)

{B}, Sacrifice a creature: Destroy target nonblack creature.

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.

Barren Moor enters the battlefield tapped.

{T}: Add {B}.

Cycling {B} ({B}, Discard this card: Draw a card.)

When Bastion of Remembrance enters the battlefield, create a 1/1 white Human Soldier creature token.

Whenever a creature you control dies, each opponent loses 1 life and you gain 1 life.

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.)

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.

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

Return up to two target creature cards with total mana value 3 or less from your graveyard to the battlefield. Put a deathtouch counter on either of them. Then put a menace counter on either of them.

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.

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.

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

Crypt of Agadeem enters the battlefield tapped.

{T}: Add {B}.

{2}, {T}: Add {B} for each black creature card in your graveyard.

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

Add {B}{B}{B}{B}.

Whenever a creature you control dies, 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.")

Whenever a creature is dealt damage, destroy it. It can't be regenerated.

As Door of Destinies enters the battlefield, choose a creature type.

Whenever you cast a spell of the chosen type, put a charge counter on Door of Destinies.

Creatures you control of the chosen type get +1/+1 for each charge counter on Door of Destinies.

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.

This spell costs {1} less to cast if an opponent controls no basic lands.

Destroy target creature.

Hagra Broodpit enters the battlefield tapped.

{T}: Add {B}.

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.)

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.

As Heraldic Banner enters the battlefield, choose a color.

Creatures you control of the chosen color get +1/+0.

{T}: Add one mana of the chosen color.

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.

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.

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.

Black spells you cast cost {1} less to cast.

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.

Enchant creature or planeswalker you control

When enchanted permanent dies or is put into exile, return that card to the battlefield under your control.

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)

Equip {0}

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

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."

Choose target creature. You lose 2 life. Until end of turn, that creature gains "When this creature dies, return it to the battlefield tapped under its owner's control."

Malakir Mire enters the battlefield tapped.

{T}: Add {B}.

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.

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

{1}{B}: Exile target card from an opponent's graveyard. If no cards are in that graveyard, flip Nezumi Graverobber.

{4}{B}: Put target creature card from a graveyard onto the battlefield under your 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.)

When Nezumi Prowler enters the battlefield, target creature you control gains deathtouch and lifelink until end of turn.

{1}{B}, {T}: Target opponent discards a card. Then if that player has no cards in hand, flip Nezumi Shortfang.

At the beginning of each opponent's upkeep, that player loses 1 life for each card fewer than three in their hand.

You draw two cards and you lose 2 life.

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.

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.

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.)

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.

Target opponent reveals their hand. You choose a card from it with mana value 3 or greater. That player discards that card.

Pelakka Caverns enters the battlefield tapped.

{T}: Add {B}.

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.

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.

{T}: Add {C}.

{T}: Add one mana of any color. Spend this mana only to cast a legendary spell.

{T}: Add one mana of any color among legendary permanents you control.

{3}, {T}, Exile Plaza of Heroes: Target legendary creature gains hexproof and indestructible until end of turn.

Polluted Mire enters the battlefield tapped.

{T}: Add {B}.

Cycling {2} ({2}, Discard this card: Draw a card.)

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 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.)

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.

Each opponent sacrifices a creature or planeswalker with the highest mana value among creatures and planeswalkers they control.

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.

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

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

{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.)

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

Equip {1}

{T}: Add {B}.

Channel -- {3}{B}, Discard Takenuma, Abandoned Mire: Mill three cards, then return a creature or planeswalker card from your graveyard to your hand. This ability costs {1} less to activate for each legendary creature you control.

Tangled Colony can't block.

When Tangled Colony dies, create X 1/1 black Rat creature tokens with "This creature can't block," where X is the amount of damage dealt to it this turn.

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.

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 this Saga enters and after your draw step, add a lore counter.)

I, II -- Each opponent creates a 1/1 black Rat Rogue creature token.

III -- Exile this Saga, then return it to the battlefield transformed under your control.

Flying, haste

When Echo of Death's Wail enters the battlefield, gain control of all Rat tokens.

Whenever Echo of Death's Wail attacks, you may sacrifice another creature. If you do, draw a card.

When Twisted Sewer-Witch enters the battlefield, create a 1/1 black Rat creature token with "This creature can't block." Then for each Rat you control, create a Wicked Role token attached to that Rat. (If you control another Role on it, put that one into the graveyard. Enchanted creature gets +1/+1. When this Aura is put into a graveyard, each opponent loses 1 life.)

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

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.

Choose two target creature cards in your graveyard. Sacrifice a creature. If you do, return the chosen cards to the battlefield tapped.

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

Draw two cards.

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.)