Muck Rats

Razortooth Rats

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)

Innocuous Rat

When this creature 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.)

Ogre Slumlord

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

Harmonized Crescendo

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Choose a creature type. Draw a card for each permanent you control of that type.

Ruthless Radrat

Squad—Exile four cards from your graveyard. (As an additional cost to cast this spell, you may pay its squad cost any number of times. When this creature enters, create that many tokens that are copies of it.)
Menace (This creature can't be blocked except by two or more creatures.)

Vanquisher's Banner

As this artifact enters, 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.

Gossip's Talent

(Gain the next level as a sorcery to add its ability.)
Whenever a creature you control enters, surveil 1.
{1}{U}: Level 2
Whenever you attack, target attacking creature with power 3 or less can't be blocked this turn.
{3}{U}: Level 3
Whenever a creature you control deals combat damage to a player, you may exile it, then return it to the battlefield under its owner's control.

Nightwhorl Hermit

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

Talisman of Dominance

{T}: Add {C}.
{T}: Add {U} or {B}. This artifact deals 1 damage to you.

Nezumi Bladeblesser

This creature has deathtouch as long as you control an artifact.
This creature has menace as long as you control an enchantment. (It can't be blocked except by two or more creatures.)

Blightbelly Rat

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

Omni-Changeling

Changeling (This card is every creature type.)
Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
You may have this creature enter as a copy of any creature on the battlefield, except it has changeling.

Edgewall Pack

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

Bloodline Bidding

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Choose a creature type. Return all creature cards of the chosen type from your graveyard to the battlefield.

Gobhobbler Rats

Hellbent — As long as you have no cards in hand, this creature gets +1/+0 and has "{B}: Regenerate this creature." (The next time it would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Improvised Arsenal

Equipped creature gets +1/+0 for each artifact you control.
{4}{R}: Create a token that's a copy of this Equipment.
Equip {R}

Swarmyard

{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.)

Valley Rotcaller

Menace
Whenever this creature attacks, each opponent loses X life and you gain X life, where X is the number of other Squirrels, Bats, Lizards, and Rats you control.

Nezumi Informant

When this creature enters, each opponent discards a card.

Rat King, Verminister

Disappear — At the beginning of your end step, if a permanent left the battlefield under your control this turn, create a 1/1 black Rat creature token and put a +1/+1 counter on Rat King.
{T}, Sacrifice three Rats: Return target creature card and all other cards with the same name as that card from your graveyard to the battlefield tapped.

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.

Nezumi Linkbreaker

When this creature dies, create a 1/1 red Mercenary creature token with "{T}: Target creature you control gets +1/+0 until end of turn. Activate only as a sorcery."

Persistent Marshstalker

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

Bog Rats

Shoreline Looter

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

Graveshifter

Changeling (This card is every creature type.)
When this creature enters, you may return target creature card from your graveyard to your hand.

Ravenous Rats

When this creature enters, target opponent discards a card.

City on Fire

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
If a source you control would deal damage to a permanent or player, it deals triple that damage instead.

Skullclamp

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

Mind Drill Assailant

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

Dimir Signet

Gathering Stone

As this artifact enters, choose a creature type.
Spells you cast of the chosen type cost {1} less to cast.
When this artifact enters and at the beginning of your upkeep, look at the top card of your library. If it's a card of the chosen type, you may reveal it and put it into your hand. If you don't put the card into your hand, you may put it into your graveyard.

Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Insatiable Frugivore

When this creature enters, create a Food token, then you may exile three cards from your graveyard. If you do, repeat this process.
{3}{B}, Sacrifice X Foods: Creatures you control get +X/+0 and gain menace until end of turn.

Reliquary Tower

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

Freya Crescent

Jump — During your turn, Freya Crescent has flying.
{T}: Add {R}. Spend this mana only to cast an Equipment spell or activate an equip ability.

Sol Ring

Wizard Class

(Gain the next level as a sorcery to add its ability.)
You have no maximum hand size.
{2}{U}: Level 2
When this Class becomes level 2, draw two cards.
{4}{U}: Level 3
Whenever you draw a card, put a +1/+1 counter on target creature you control.

Mudflat Village

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

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 this creature.

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.

Engine Rat

Deathtouch
{5}{B}: Each opponent loses 2 life.

Wick's Patrol

When this creature 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.

Collective Inferno

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
As this enchantment enters, choose a creature type.
Double all damage that sources you control of the chosen type would deal.

Swamp

Thought Vessel

Rimefire Torque

As this artifact enters, choose a creature type.
Whenever a permanent you control of the chosen type enters, put a charge counter on this artifact.
{T}, Remove three charge counters from this artifact: When you next cast an instant or sorcery spell this turn, copy it. You may choose new targets for the copy.

Undercity Dire Rat

Rat Tail — When this creature dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

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.

Patchwork Banner

As this artifact enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
{T}: Add one mana of any color.

Harried Spearguard

Haste
When this creature dies, create a 1/1 black Rat creature token with "This token can't block."

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.

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 token 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.

Changeling Wayfinder

Changeling (This card is every creature type.)
When this creature enters, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Chittering Witch

When this creature enters, 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.

Burglar Rat

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 there are seven or more cards in your graveyard, creatures your opponents control get -1/-0.

Rats of Rath

{B}: Destroy target artifact, creature, or land you control.

Proft's Eidetic Memory

When Proft's Eidetic Memory enters, draw a card.
You have no maximum hand size.
At the beginning of combat on your turn, if you've drawn more than one card this turn, put X +1/+1 counters on target creature you control, where X is the number of cards you've drawn this turn minus one.

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.

Swarmyard Massacre

Create two 1/1 green Squirrel creature tokens. Then each creature that isn't an Insect, Rat, Spider, or Squirrel gets -1/-1 until end of turn for each creature you control that's an Insect, Rat, Spider, or Squirrel.

Tunnel Rats

{4}{B}: Return this card from your graveyard to the battlefield tapped.

Arcane Signet

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

Firdoch Core

Changeling (This card is every creature type.)
{T}: Add one mana of any color.
{4}: This artifact becomes a 4/4 artifact creature until end of turn.

Elephant-Rat

Menace (This creature can't be blocked except by two or more creatures.)

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 this Equipment to that creature.
Equip {2}

Echoing Assault

Creature tokens you control have menace.
Whenever you attack a player, choose target nontoken creature that's attacking that player. Create a token that's a copy of that creature, except it's 1/1. The token enters tapped and attacking that player. Sacrifice it at the beginning of the next end step.

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.)