Swamp

Vren, the Relentless

Ward {2}
If a creature an opponent controls would die, exile it instead.
At the beginning of each end step, create X 1/1 black Rat creature tokens with "This creature gets +1/+1 for each other Rat you control," where X is the number of creatures your opponents controlled that were exiled this turn.

Ravenous Rats

When Ravenous Rats enters, target opponent discards a card.

Shoreline Looter

Shoreline Looter can't be blocked.
Threshold — Whenever Shoreline Looter deals combat damage to a player, draw a card. Then discard a card unless seven or more cards are in your graveyard.

Crippling Fear

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

Inspiration

Sword-Point Diplomacy

Reveal the top three cards of your library. For each of those cards, put that card into your hand unless any opponent pays 3 life. Then exile the rest.

Demon's Disciple

When Demon's Disciple enters, each player sacrifices a creature or planeswalker.

Drainpipe Vermin

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

Fleshbag Marauder

When Fleshbag Marauder enters, each player sacrifices a creature.

Diresight

Surveil 2, then draw two cards. You lose 2 life. (To surveil 2, look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Grave Pact

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

Overwhelming Forces

Destroy all creatures target opponent controls. Draw a card for each creature destroyed this way.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Watery Grave

({T}: Add {U} or {B}.)
As Watery Grave enters, you may pay 2 life. If you don't, it enters tapped.

Obsessive Search

Draw a card.
Madness {U} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Gnawing Vermin

When Gnawing Vermin enters, target player mills two cards.
When Gnawing Vermin dies, target creature you don't control gets -1/-1 until end of turn.

Karumonix, the Rat King

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.

Rottenmouth Viper

As an additional cost to cast this spell, you may sacrifice any number of nonland permanents. This spell costs {1} less to cast for each permanent sacrificed this way.
Whenever Rottenmouth Viper enters or attacks, put a blight counter on it. Then for each blight counter on it, each opponent loses 4 life unless that player sacrifices a nonland permanent or discards a card.

Nightwhorl Hermit

Vigilance
Threshold — As long as seven or more cards are in your graveyard, Nightwhorl Hermit gets +1/+0 and can't be blocked.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Piper of the Swarm

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.

Shoot the Sheriff

Destroy target non-outlaw creature. (Assassins, Mercenaries, Pirates, Rogues, and Warlocks are outlaws. Everyone else is fair game.)

Quick Study

Nadier's Nightblade

Whenever a token you control leaves the battlefield, each opponent loses 1 life and you gain 1 life.

Mirkwood Bats

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

Wick's Patrol

When Wick's Patrol enters, mill three cards. When you do, target creature an opponent controls gets -X/-X until end of turn, where X is the greatest mana value among cards in your graveyard.

Crypt Ghast

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
Whenever you tap a Swamp for mana, add an additional {B}.

Breathe Your Last

Destroy target creature or planeswalker. You gain 1 life for each of its colors.

Murder

Gravelighter

Flying
When Gravelighter enters, draw a card if a creature died this turn. Otherwise, each player sacrifices a creature.

Pestilence

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

Forever Young

Put any number of target creature cards from your graveyard on top of your library.
Draw a card.

Mind Spiral

Gift a tapped Fish (You may promise an opponent a gift as you cast this spell. If you do, they create a tapped 1/1 blue Fish creature token before its other effects.)
Target player draws three cards. If the gift was promised, tap target creature an opponent controls and put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)

Black Market

Whenever a creature dies, put a charge counter on Black Market.
At the beginning of your first main phase, add {B} for each charge counter on Black Market.

Divination

Raise Dead

Return target creature card from your graveyard to your hand.

Walk the Plank

Daggerfang Duo

Deathtouch
When Daggerfang Duo enters, you may mill two cards. (You may put the top two cards of your library into your graveyard.)

Soured Springs

Soured Springs enters tapped.
When Soured Springs enters, it deals 1 damage to target opponent.
{T}: Add {U} or {B}.

Thought Shucker

Threshold — {1}{U}: Put a +1/+1 counter on Thought Shucker and draw a card. Activate only if seven or more cards are in your graveyard and only once.

Consumed by Greed

Gift a card (You may promise an opponent a gift as you cast this spell. If you do, they draw a card before its other effects.)
Target opponent sacrifices a creature with the greatest power among creatures they control. If the gift was promised, return target creature card from your graveyard to your hand.

This creature gets +1/+1 for each other Rat you control.

Swarmyard

{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.)

Mindwhisker

At the beginning of your upkeep, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Threshold — As long as seven or more cards are in your graveyard, creatures your opponents control get -1/-0.

Sol Ring

Ratcatcher

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.

Tangled Colony

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.

Plaguecrafter

When Plaguecrafter enters, each player sacrifices a creature or planeswalker. Each player who can't discards a card.

Doom Blade

Lilypad Village

{T}: Add {C}.
{T}: Add {U}. Spend this mana only to cast a creature spell.
{U}, {T}: Surveil 2. Activate only if a Bird, Frog, Otter, or Rat entered the battlefield under your control this turn.

Island

Voracious Vermin

When Voracious Vermin enters, 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.

Gravepurge

Dutiful Return

Return up to two target creature cards from your graveyard to your hand.

Burglar Rat

When Burglar Rat enters, each opponent discards a card.

Barter in Blood

Dimir Signet

Fell Mire

As Fell Mire enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {B}.

Fell the Profane

Fell the Profane // Fell Mire

Typhoid Rats

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

Mudflat Village

{T}: Add {C}.
{T}: Add {B}. Spend this mana only to cast a creature spell.
{1}{B}, {T}, Sacrifice Mudflat Village: Return target Bat, Lizard, Rat, or Squirrel card from your graveyard to your hand.

Fish

Fell

Dismal Backwater

Dismal Backwater enters tapped.
When Dismal Backwater enters, you gain 1 life.
{T}: Add {U} or {B}.

Psychic Whorl

Target opponent discards two cards. Then if you control a Rat, surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Incriminate

Choose two target creatures controlled by the same player. That player sacrifices one of them.

Hazel's Nocturne

Return up to two target creature cards from your graveyard to your hand. Each opponent loses 2 life and you gain 2 life.

Macabre Waltz

Return up to two target creature cards from your graveyard to your hand, then discard a card.

Cremate

Exile target card from a graveyard.
Draw a card.

Merciless Executioner

When Merciless Executioner enters, each player sacrifices a creature.

Pack Rat

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.

Thornplate Intimidator

Offspring {3} (You may pay an additional {3} as you cast this spell. If you do, when this creature enters, create a 1/1 token copy of it.)
When this creature enters, target opponent loses 3 life unless they sacrifice a nonland permanent or discard a card.

Polluted Delta

{T}, Pay 1 life, Sacrifice Polluted Delta: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Dark Ritual

Accursed Marauder

When Accursed Marauder enters, each player sacrifices a nontoken creature.

Lash of the Balrog

As an additional cost to cast this spell, sacrifice a creature or pay {4}.
Destroy target creature.