As Adaptive Automaton enters the battlefield, choose a creature type.

Adaptive Automaton is the chosen type in addition to its other types.

Other creatures you control of the chosen type get +1/+1.

Black creatures get +1/+1.

Bog Rats can't be blocked by Walls.

Bojuka Bog enters the battlefield tapped.

When Bojuka Bog enters the battlefield, exile target player's graveyard.

{T}: Add {B}.

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.

As Caged Sun enters the battlefield, choose a color.

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

Whenever a land's ability causes you to add one or more mana of the chosen color, add one additional mana of that color.

Whenever Carrion Rats attacks or blocks, any player may exile a card from their graveyard. If a player does, Carrion Rats assigns no combat damage this turn.

Charcoal Diamond enters the battlefield tapped.

{T}: Add {B}.

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.

{X}: Crypt Rats deals X damage to each creature and each player. Spend only black mana on X.

Add {B}{B}{B}.

Search your library for a card, put that card into your hand, then shuffle.

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

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

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

Spells your opponents cast cost {2} more to cast.

At the beginning of your end step, each opponent loses 1 life.

At the beginning of combat on your turn, if you both own and control Graf Rats and a creature named Midnight Scavengers, exile them, then meld them into Chittering Host.

Each opponent loses 1 life for each creature 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.)

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.

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.

{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.

Buyback {4} (You may pay an additional {4} as you cast this spell. If you do, put this card into your hand as it resolves.)

Create a 1/1 black Rat creature token.

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.

When Midnight Scavengers enters the battlefield, you may return target creature card with mana value 3 or less from your graveyard to your hand.

(Melds with Graf Rats.)

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}.

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

Destroy target creature.

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.

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.

Nyx Lotus enters the battlefield tapped.

{T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)

As Obelisk of Urd enters the battlefield, choose a creature type.

Creatures you control of the chosen type get +2/+2.

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.)

{T}: Add one mana of any color.

{1}, {T}: Untap target legendary creature you control.

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

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.

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}: Target blocking creature gets -1/-1 until end of turn.

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.

{B}: Destroy target artifact, creature, or land you control.

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.)

You have no maximum hand size.

{T}: Add {C}.

Choose one --

• Return target creature card from your graveyard to your hand.

• Return two target creature cards that share a creature type from your graveyard to your hand.

{T}: Add {C}.

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

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.

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

Target player draws two cards and loses 2 life.

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.

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

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.)

{T}: Add {C}{C}. Activate only if you control five or more lands.

When Thriving Rats enters the battlefield, you get {E}{E} (two energy counters).

Whenever Thriving Rats attacks, you may pay {E}{E}. If you do, put a +1/+1 counter on it.

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.

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.)

({T}: Add {B}.)

Witch's Cottage enters the battlefield tapped unless you control three or more other Swamps.

When Witch's Cottage enters the battlefield untapped, you may put target creature card from your graveyard on top of your library.

Whenever Zulaport Cutthroat or another creature you control dies, each opponent loses 1 life and you gain 1 life.