Add {B}{B}{B}.

As this artifact enters, 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.

Vigilance This creature can't be blocked by creatures with power 2 or greater. Whenever this creature attacks, up to one target artifact, creature, or planeswalker an opponent controls loses all abilities until your next turn. If it's a creature, it also has base power and toughness 2/2 until your next turn.

This creature gets +1/+0 for each other Rat you control. Threshold — Whenever you attack with one or more Rats, if seven or more cards are in your graveyard, you may pay {2}{B}. If you do, return this card from your graveyard to the battlefield tapped and attacking.

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.)

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

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

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

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

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

Destroy target nonblack creature.

You may sacrifice a nontoken black creature rather than pay this spell's mana cost. Each opponent sacrifices a creature or planeswalker with the greatest mana value among creatures and planeswalkers they control.

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

Each player sacrifices a creature of their choice.

Choose a creature type. Destroy all creatures that aren't of the chosen type.

Each opponent sacrifices a creature of their choice. If you control a Liliana planeswalker, each opponent also discards a card.

Each opponent separates the creatures they control into two piles. For each opponent, you choose one of their piles. Each opponent sacrifices the creatures in their chosen pile. (Piles can be empty.)

Each opponent sacrifices a creature or enchantment of their choice.

At the beginning of the end step, if no creatures are on the battlefield, sacrifice this enchantment. {B}: This enchantment deals 1 damage to each creature and each player.

Spree (Choose one or more additional costs.) + {1} — Target opponent sacrifices half the creatures they control of their choice, rounded up. + {2} — Target opponent discards half the cards in their hand, rounded up. + {2} — Target opponent loses half their life, rounded up.

Choose one — • Each opponent sacrifices a nontoken creature of their choice. • Each opponent sacrifices a creature token of their choice. • Each opponent sacrifices a planeswalker of their choice.

Ninjutsu {B} ({B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.) Whenever this creature deals combat damage to a player, exile up to two target cards from that player's graveyard.

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

When this creature enters, each opponent discards a card.

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

When this creature enters, each opponent discards a card.

Whenever another Rat you control enters, 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 token can't block."

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.

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

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.

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 token: Add one mana of any color.")

Choose a creature type. Draw a card for each permanent you control of that type.

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.) Other Rats you control have toxic 1. When Karumonix enters, 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.

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 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.

As this land enters, you may reveal an Island or Swamp card from your hand. If you don't, this land enters tapped. {T}: Add {U} or {B}.

{1}, {T}: Add {U}{B}.

This land enters tapped unless you control an Island or a Swamp. {T}: Add {U} or {B}.

This land enters tapped unless you control two or more other lands. {T}: Add {U} or {B}.

({T}: Add {U} or {B}.) This land enters tapped unless you control two or more basic lands.

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

{T}: Add {C}. {T}: Add {U} or {B}. Activate only if you control a Swamp.