When Lord Skitter's Butcher enters the battlefield, choose one — • Create a 1/1 black Rat creature token with "This creature can't block." • You may sacrifice another creature. If you do, scry 2, then draw a card. • Creatures you control gain menace until end of turn.

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."

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.)

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.

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

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

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

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.

As Species Specialist enters the battlefield, choose a creature type. Whenever a creature of the chosen type dies, you may draw a card.

{1}{B}, Sacrifice a creature: You gain 1 life and draw a card.

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.

As an additional cost to cast this spell, discard a card or pay 3 life. Destroy target creature or planeswalker.

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

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}. {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.)

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.

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.

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

Exile target creature with mana value 3 or greater.

Destroy target nonartifact creature.

Destroy target creature or planeswalker.

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

Destroy target creature.

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.

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