Konda's Banner

Konda's Banner can be attached only to a legendary creature.
Creatures that share a color with equipped creature get +1/+1.
Creatures that share a creature type with equipped creature get +1/+1.
Equip {2}

Doom Blade

Door of Destinies

As Door of Destinies enters the battlefield, choose a creature type.
Whenever you cast a spell of the chosen type, put a charge counter on Door of Destinies.
Creatures you control of the chosen type get +1/+1 for each charge counter on Door of Destinies.

Lightning Greaves

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

Carrion Rats

Whenever Carrion Rats attacks or blocks, any player may exile a card from their graveyard. If a player does, Carrion Rats assigns no combat damage this turn.

Rabid Rats

{T}: Target blocking creature gets -1/-1 until end of turn.

Price of Fame

This spell costs {2} less to cast if it targets a legendary creature.
Destroy target creature.
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.)

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.

Phyrexian Arena

At the beginning of your upkeep, you draw a card and you lose 1 life.

Relentless Rats

Relentless Rats gets +1/+1 for each other creature on the battlefield named Relentless Rats.
A deck can have any number of cards named Relentless Rats.

Sinuous Vermin

{3}{B}{B}: Monstrosity 3. (If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.)
As long as Sinuous Vermin is monstrous, it has menace. (It can't be blocked except by two or more creatures.)

Damnable Pact

Target player draws X cards and loses X life.

Skullclamp

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

Cast Down

Thriving Rats

When Thriving Rats enters the battlefield, you get {E}{E} (two energy counters).
Whenever Thriving Rats attacks, you may pay {E}{E}. If you do, put a +1/+1 counter on it.

Elixir of Immortality

{2}, {T}: You gain 5 life. Shuffle Elixir of Immortality and your graveyard into their owner's library.

Gutter Skulk

Crypt Rats

{X}: Crypt Rats deals X damage to each creature and each player. Spend only black mana on X.

Rat Colony

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

Drainpipe Vermin

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

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.

Murder

Adaptive Automaton

As Adaptive Automaton enters the battlefield, choose a creature type.
Adaptive Automaton is the chosen type in addition to its other types.
Other creatures you control of the chosen type get +1/+1.

Bontu's Monument

Black creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, each opponent loses 1 life and you gain 1 life.

Ogre Slumlord

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

Vanquisher's Banner

As Vanquisher's Banner enters the battlefield, 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.

Rancid Rats

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.)

Sign in Blood

Target player draws two cards and loses 2 life.

Zodiac Rat

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)

Swarm of Rats

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

Muck Rats

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.

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.

Shadowspear

Equipped creature gets +1/+1 and has trample and lifelink.
{1}: Permanents your opponents control lose hexproof and indestructible until end of turn.
Equip {2}

Demonic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Greed

Blood Divination

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

Altar's Reap

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

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Bad Moon

Swamp

Rats of Rath

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

Foul-Tongue Shriek

Target opponent loses 1 life for each attacking creature you control. You gain that much life.

Burglar Rat

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

Nezumi Cutthroat

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

Gnat Miser

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

Ayara, First of Locthwain

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.

Rotting Rats

When Rotting Rats enters the battlefield, each player discards a card.
Unearth {1}{B} ({1}{B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

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.

Sewer Rats

{B}, Pay 1 life: Sewer Rats gets +1/+0 until end of turn. Activate no more than three times each turn.

Metallic Mimic

As Metallic Mimic enters the battlefield, 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 the battlefield with an additional +1/+1 counter on it.

Read the Bones

Scry 2, then draw two cards. You lose 2 life.

Nezumi Ronin

Bushido 1 (Whenever this creature blocks or becomes blocked, it gets +1/+1 until end of turn.)

Dark Prophecy

Whenever a creature you control dies, you draw a card and you lose 1 life.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Ruin Rat

Deathtouch
When Ruin Rat dies, exile target card from an opponent's graveyard.

Gravepurge

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

Skullsnatcher

Ninjutsu {B} ({B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Skullsnatcher deals combat damage to a player, exile up to two target cards from that player's graveyard.

Stoneforge Masterwork

Equipped creature gets +1/+1 for each other creature you control that shares a creature type with it.
Equip {2}

Night's Whisper

Underworld Connections

Enchant land
Enchanted land has "{T}, Pay 1 life: Draw a card."

Chittering Rats

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

Ravenous Rats

When Ravenous Rats enters the battlefield, target opponent discards a card.

Typhoid Rats

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

Hall of Triumph

As Hall of Triumph enters the battlefield, choose a color.
Creatures you control of the chosen color get +1/+1.

Pestilence Rats

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.)

Coat of Arms

Each creature gets +1/+1 for each other creature on the battlefield that shares at least one creature type with it. (For example, if two Goblin Warriors and a Goblin Shaman are on the battlefield, each gets +2/+2.)