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.

Whenever another creature you control dies, draw a card if it was attacking. Otherwise, Garna, Bloodfist of Keld deals 1 damage to each opponent.

Whenever a creature deals combat damage to one of your opponents, its controller may pay 1 life. If they do, they draw a card. {4}{B}{B}{B}, Discard X cards: Exile the top X cards of target opponent's library. You may play lands and cast spells from among cards exiled this way without paying their mana costs.

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.

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

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

Deathtouch Whenever a creature you control with deathtouch attacks, each opponent loses 1 life and you gain 1 life. Whenever a creature you control with deathtouch deals damage to a planeswalker, destroy that planeswalker.

Menace Whenever Ogre Chitterlord enters the battlefield or attacks, create two 1/1 black Rat creature tokens with "This creature can't block." Then if you control five or more Rats, each Rat you control gets +2/+0 until end of turn.

Captive Audience enters the battlefield under the control of an opponent of your choice. At the beginning of your upkeep, choose one that hasn't been chosen — • Your life total becomes 4. • Discard your hand. • Each opponent creates five 2/2 black Zombie creature tokens.

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.

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.

Whenever you draw your second card each turn, create two 1/1 black Rat creature tokens.

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

Create X 1/1 black Rat creature tokens with "This creature can't block." Creatures you control gain haste until end of turn.

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.)

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

When Chittering Rats enters the battlefield, target opponent puts a card from their hand on top of their library.

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

Haste When Hellhole Rats enters the battlefield, target player discards a card. Hellhole Rats deals damage to that player equal to that card's mana value.

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.

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.

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."

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.

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.

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.)

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.)

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

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 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.

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

Up to one target creature gets -1/-1 until end of turn. You create a 1/1 black Rat creature token with "This creature can't block."

Whenever a creature enters the battlefield under your control, Impact Tremors deals 1 damage to each opponent.

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

Whenever a creature you control with power 2 or less attacks, Raid Bombardment deals 1 damage to the player or planeswalker that creature is attacking.