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 that were exiled under your opponents' control this turn.

Agate Assault

Choose one —
• Agate Assault deals 4 damage to target creature. If that creature would die this turn, exile it instead.
• Exile target artifact.

Inner Struggle

Target creature deals damage to itself equal to its power.

Wick, the Whorled Mind

Whenever Wick or another Rat you control enters, create a 1/1 black Snail creature token if you don't control a Snail. Otherwise, put a +1/+1 counter on a Snail you control.
{U}{B}{R}, Sacrifice a Snail: Wick deals damage equal to the sacrificed creature's power to each opponent. Then draw cards equal to the sacrificed creature's power.

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.

Lord Skitter's Butcher

When Lord Skitter's Butcher enters, 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.

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.)

Splash Portal

Exile target creature you control, then return it to the battlefield under its owner's control. If that creature is a Bird, Frog, Otter, or Rat, draw a card.

Sword of the Squeak

Equipped creature gets +1/+1 for each creature you control with base power or toughness 1.
Whenever a Hamster, Mouse, Rat, or Squirrel you control enters, you may attach Sword of the Squeak to that creature.
Equip {2}

Eaten Alive

As an additional cost to cast this spell, sacrifice a creature or pay {3}{B}.
Exile target creature or planeswalker.

Volatile Fjord

({T}: Add {U} or {R}.)
Volatile Fjord enters tapped.

Turn Aside

Counter target spell that targets a permanent you control.

Totentanz, Swarm Piper

Whenever Totentanz, Swarm Piper or another nontoken creature you control dies, create a 1/1 black Rat creature token with "This creature can't block."
{1}{B}: Target attacking Rat you control gains deathtouch until end of turn.

Littjara Kinseekers

Changeling (This card is every creature type.)
When Littjara Kinseekers enters, if you control three or more creatures that share a creature type, put a +1/+1 counter on Littjara Kinseekers, then scry 1.

Ice Tunnel

({T}: Add {U} or {B}.)
Ice Tunnel enters tapped.

Grievous Wound

Enchant player
Enchanted player can't gain life.
Whenever enchanted player is dealt damage, they lose half their life, rounded up.

Ossuary Rats

When Ossuary Rats enters, it deals X damage to target creature or planeswalker an opponent controls, where X is the number of creature cards in your graveyard.

Peculiar Lighthouse

Peculiar Lighthouse enters tapped unless a player has 13 or less life.
{T}: Add {U} or {R}.

Metallic Mimic

As Metallic Mimic enters, choose a creature type.
Metallic Mimic is the chosen type in addition to its other types.
Each other creature you control of the chosen type enters with an additional +1/+1 counter on it.

Copycrook

You may have Copycrook enter as a copy of any creature on the battlefield, except it has "Whenever this creature attacks, it connives." (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on this creature.)

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 of their choice or discards a card.

Thriving Isle

Thriving Isle enters tapped. As it enters, choose a color other than blue.
{T}: Add {U} or one mana of the chosen color.

Murky Sewer

Murky Sewer enters tapped unless a player has 13 or less life.
{T}: Add {U} or {B}.

Succumb to Temptation

Ravenous Rats

When Ravenous Rats enters, target opponent discards a card.

Mad Ratter

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

Swamp

Breathe Your Last

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

Dead Weight

Enchant creature
Enchanted creature gets -2/-2.

Gloomlake Verge

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

Distemper of the Blood

Target creature gets +2/+2 and gains trample until end of turn.
Madness {R} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Tattered Ratter

Whenever a Rat you control becomes blocked, it gets +2/+0 until end of turn.

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.

Ghost Vacuum

{T}: Exile target card from a graveyard.
{6}, {T}, Sacrifice Ghost Vacuum: Put each creature card exiled with Ghost Vacuum onto the battlefield under your control with a flying counter on it. Each of them is a 1/1 Spirit in addition to its other types. Activate only as a sorcery.

Edgewall Pack

Menace (This creature can't be blocked except by two or more creatures.)
When Edgewall Pack enters, create a 1/1 black Rat creature token with "This creature can't block."

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Restless Spire

Restless Spire enters tapped.
{T}: Add {U} or {R}.
{U}{R}: Until end of turn, Restless Spire becomes a 2/1 blue and red Elemental creature with "During your turn, this creature has first strike." It's still a land.
Whenever Restless Spire attacks, scry 1.

Raze the Effigy

Choose one —
• Destroy target artifact.
• Target attacking creature gets +2/+2 until end of turn.

Submerged Boneyard

Submerged Boneyard enters tapped.
{T}: Add {U} or {B}.

Blood Pact

Target player draws two cards and loses 2 life.

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.)

Redcap Gutter-Dweller

Menace
When this creature enters, create two 1/1 black Rat creature tokens with "This token can't block."
At the beginning of your upkeep, you may sacrifice another creature. If you do, put a +1/+1 counter on this creature and exile the top card of your library. You may play that card this turn.

Captivating Cave

{T}: Add {C}.
{1}, {T}: Add one mana of any color.
{4}, {T}, Sacrifice Captivating Cave: Put two +1/+1 counters on target creature. Activate only as a sorcery.

Blightbelly Rat

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
When Blightbelly Rat dies, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Mind Drill Assailant

Threshold — As long as seven or more cards are in your graveyard, Mind Drill Assailant gets +3/+0.
{2}{U/B}: Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Ogre Slumlord

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

Thriving Bluff

Thriving Bluff enters tapped. As it enters, choose a color other than red.
{T}: Add {R} or one mana of the chosen color.

Barkform Harvester

Changeling (This card is every creature type.)
Reach
{2}: Put target card from your graveyard on the bottom of your library.

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.

Island

Sulfurous Mire

({T}: Add {B} or {R}.)
Sulfurous Mire enters tapped.

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.

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.

Tidecaller Mentor

Menace
Threshold — When Tidecaller Mentor enters, if seven or more cards are in your graveyard, return up to one target nonland permanent to its owner's hand.

Devious Cover-Up

Counter target spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard. You may shuffle up to four target cards from your graveyard into your library.

Field of Ruin

{T}: Add {C}.
{2}, {T}, Sacrifice Field of Ruin: Destroy target nonbasic land an opponent controls. Each player searches their library for a basic land card, puts it onto the battlefield, then shuffles.

Fell

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.

Revenge of the Rats

Create a tapped 1/1 black Rat creature token for each creature card in your graveyard.
Flashback {2}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

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.

Highland Lake

Highland Lake enters tapped.
{T}: Add {U} or {R}.

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Bloodfell Caves

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {B} or {R}.

Boon of Emrakul

Enchant creature
Enchanted creature gets +3/-3.

Old Flitterfang

Flying
At the beginning of each end step, if a creature died this turn, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")
{2}{B}, Sacrifice another creature or artifact: Old Flitterfang gets +2/+2 until end of turn.

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 of their choice or discard a card.

Mountain

Uncharted Haven

This land enters tapped. As it enters, choose a color.
{T}: Add one mana of the chosen color.

Murder

Cinder Barrens

Cinder Barrens enters tapped.
{T}: Add {B} or {R}.

Persistent Marshstalker

Persistent Marshstalker 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 Persistent Marshstalker from your graveyard to the battlefield tapped and attacking.

Refurbished Familiar

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Flying
When Refurbished Familiar enters, each opponent discards a card. For each opponent who can't, you draw a card.

Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Draw a card.

Razortrap Gorge

Razortrap Gorge enters tapped unless a player has 13 or less life.
{T}: Add {B} or {R}.

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.

Innocuous Rat

When Innocuous Rat dies, manifest dread. (Look at the top two cards of your library. Put one onto the battlefield face down as a 2/2 creature and the other into your graveyard. Turn it face up any time for its mana cost if it's a creature card.)

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.

Three Tree City

As Three Tree City enters, choose a creature type.
{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to the number of creatures you control of the chosen type.

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.

Pest Problem

Create two 1/1 black Rat creature tokens with "This creature can't block." (Then exile this card. You may cast the creature later from exile.)

Ratcatcher Trainee

During your turn, Ratcatcher Trainee has first strike.

Ratcatcher Trainee // Pest Problem

Three Tree Mascot

Changeling (This card is every creature type.)
{1}: Add one mana of any color. Activate only once each turn.

Rabid Gnaw

Target creature you control gets +1/+0 until end of turn. Then it deals damage equal to its power to target creature you don't control.

Hedron Archive

{T}: Add {C}{C}.
{2}, {T}, Sacrifice this artifact: Draw two cards.

Sinister Monolith

At the beginning of combat on your turn, each opponent loses 1 life and you gain 1 life.
{T}, Pay 2 life, Sacrifice Sinister Monolith: Draw two cards. Activate only as a sorcery.