Charging Hooligan

Whenever Charging Hooligan attacks, it gets +1/+0 until end of turn for each attacking creature. If a Rat is attacking, Charging Hooligan gains trample until end of turn.

Zulaport Cutthroat

Whenever Zulaport Cutthroat or another creature you control dies, each opponent loses 1 life and you gain 1 life.

Foreboding Ruins

As Foreboding Ruins enters the battlefield, you may reveal a Swamp or Mountain card from your hand. If you don't, Foreboding Ruins enters the battlefield tapped.
{T}: Add {B} or {R}.

Gutter Skulk

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.

Shared Animosity

Whenever a creature you control attacks, it gets +1/+0 until end of turn for each other attacking creature that shares a creature type with it.

Grave Pact

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

Wave of Rats

Trample
When Wave of Rats dies, if it dealt combat damage to a player this turn, return it to the battlefield under its owner's control.
Blitz {4}{B} (If you cast this spell for its blitz cost, it gains haste and "When this creature dies, draw a card." Sacrifice it at the beginning of the next end step.)

Rat Out

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."

Sol Ring

Spiteful Hexmage

When Spiteful Hexmage enters the battlefield, create a Cursed Role token attached to target creature you control. (If you control another Role on it, put that one into the graveyard. Enchanted creature is 1/1.)

Mountain

Raging Battle Mouse

The second spell you cast each turn costs {1} less to cast.
Celebration — At the beginning of combat on your turn, if two or more nonland permanents entered the battlefield under your control this turn, target creature you control gets +1/+1 until end of turn.

Herald's Horn

As Herald's Horn enters the battlefield, choose a creature type.
Creature spells you cast of the chosen type cost {1} less to cast.
At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.

Embereth Veteran

{1}, Sacrifice Embereth Veteran: Create a Young Hero Role token attached to another target creature. (If you control another Role on it, put that one into the graveyard. Enchanted creature has "Whenever this creature attacks, if its toughness is 3 or less, put a +1/+1 counter on it.")

Twisted Sewer-Witch

When Twisted Sewer-Witch enters the battlefield, create a 1/1 black Rat creature token with "This creature can't block." Then for each Rat you control, create a Wicked Role token attached to that Rat. (If you control another Role on it, put that one into the graveyard. Enchanted creature gets +1/+1. When this Aura is put into a graveyard, each opponent loses 1 life.)

Command Tower

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

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

As long as it's your turn, Ratcatcher Trainee has first strike.

Ratcatcher Trainee // Pest Problem

Vampiric Rites

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

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.

Smoldering Marsh

({T}: Add {B} or {R}.)
Smoldering Marsh enters the battlefield tapped unless you control two or more basic lands.

Three Bowls of Porridge

{2}, {T}: Choose one that hasn't been chosen —
• Three Bowls of Porridge deals 2 damage to target creature.
• Tap target creature.
• Sacrifice Three Bowls of Porridge. You gain 3 life.

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.

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.

Rakdos Signet

Mahadi, Emporium Master

At the beginning of your end step, create a Treasure token for each creature that died this turn. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Terminate

Destroy target creature. It can't be regenerated.

Septic Rats

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Whenever Septic Rats attacks, if defending player is poisoned, it gets +1/+1 until end of turn.

Arcane Signet

Garna, Bloodfist of Keld

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

Impact Tremors

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

Mirkwood Bats

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

Rat Colony

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

Become Brutes

One or two target creatures each gain haste until end of turn. For each of those creatures, create a Monster Role token attached to it. (If you control another Role on it, put that one into the graveyard. Enchanted creature gets +1/+1 and has trample.)

Warehouse Tabby

Whenever an enchantment you control is put into a graveyard from the battlefield, create a 1/1 black Rat creature token with "This creature can't block."
{1}{B}: Warehouse Tabby gains deathtouch until end of turn.

Song of Totentanz

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

Witch's Mark

You may discard a card. If you do, draw two cards.
Create a Wicked Role token attached to up to one target creature you control. (If you control another Role on it, put that one into the graveyard. Enchanted creature gets +1/+1. When this Aura is put into a graveyard, each opponent loses 1 life.)

Burglar Rat

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

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.

Lord Skitter, Sewer King

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."

Harried Spearguard

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

Evolving Wilds

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Skullclamp

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

Swamp

Gnat Miser

Each opponent's maximum hand size is reduced by one.

Lord Skitter's Blessing

When Lord Skitter's Blessing enters the battlefield, create a Wicked Role token attached to target creature you control. (Enchanted creature gets +1/+1. When this Aura is put into a graveyard, each opponent loses 1 life.)
At the beginning of your draw step, if you control an enchanted creature, you lose 1 life and you draw an additional card.

Stronghold Rats

Shadow (This creature can block or be blocked by only creatures with shadow.)
Whenever Stronghold Rats deals combat damage to a player, each player discards a card.

Thought Vessel

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

Merry Bards

When Merry Bards enters the battlefield, you may pay {1}. When you do, create a Young Hero Role token attached to target creature you control. (If you control another Role on it, put that one into the graveyard. Enchanted creature has "Whenever this creature attacks, if its toughness is 3 or less, put a +1/+1 counter on it.")

Voracious Vermin

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.

Not Dead After All

Until end of turn, target creature you control gains "When this creature dies, return it to the battlefield tapped under its owner's control, then create a Wicked Role token attached to it." (Enchanted creature gets +1/+1. When this Aura is put into a graveyard, each opponent loses 1 life.)

Gnawing Crescendo

Creatures you control get +2/+0 until end of turn. Whenever a nontoken creature you control dies this turn, create a 1/1 black Rat creature token with "This creature can't block."

Charming Scoundrel

Haste
When Charming Scoundrel enters the battlefield, choose one —
• Discard a card, then draw a card.
• Create a Treasure token.
• Create a Wicked Role token attached to target creature you control.

Marrow-Gnawer

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.

Kuro's Taken

Bushido 1 (Whenever this creature blocks or becomes blocked, it gets +1/+1 until end of turn.)
{1}{B}: Regenerate Kuro's Taken.

Lord Skitter's Butcher

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.

Corrupted Conviction

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards.

Price of Beauty

Create a Wicked Role token attached to target creature you control. (Then exile this card. You may cast the creature later from exile.)

Conceited Witch

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

Conceited Witch // Price of Beauty

Candy Trail

When Candy Trail enters the battlefield, scry 2.
{2}, {T}, Sacrifice Candy Trail: You gain 3 life and draw a card.

Tattered Ratter

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

Swarm of Rats

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

Ogre Slumlord

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

Typhoid Rats

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

Raid Bombardment

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.

Village Rites

Path of Ancestry

Path of Ancestry enters the battlefield tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)