Sol Ring

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.

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.

Rat Colony

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

Ashcoat of the Shadow Swarm

Whenever Ashcoat attacks or blocks, other Rats you control get +X/+X until end of turn, where X is the number of Rats you control.
At the beginning of your end step, you may mill four cards. If you do, return up to two Rat creature cards from your graveyard to your hand. (To mill a card, put the top card of your library into your graveyard.)

Bastion of Remembrance

When this enchantment enters, create a 1/1 white Human Soldier creature token.
Whenever a creature you control dies, each opponent loses 1 life and you gain 1 life.

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.

Filth

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
As long as this card is in your graveyard and you control a Swamp, creatures you control have swampwalk.

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.)

Path of Ancestry

This land enters 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.)

Door of Destinies

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

Grave Pact

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

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.

Black Market

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

Gray Merchant of Asphodel

When this creature enters, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Deadly Dispute

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Ashnod's Altar

Caged Sun

As this artifact enters, choose a color.
Creatures you control of the chosen color get +1/+1.
Whenever a land's ability causes you to add one or more mana of the chosen color, add an additional one mana of that color.

Deadly Rollick

If you control a commander, you may cast this spell without paying its mana cost.
Exile target creature.

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.

Lord Skitter, Sewer King

Whenever another Rat you control enters, 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 token can't block."

Cabal Coffers

{2}, {T}: Add {B} for each Swamp you control.

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.

Skullclamp

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

Chronicle of Victory

As Chronicle of Victory enters, choose a creature type.
Creatures you control of the chosen type get +2/+2 and have first strike and trample.
Whenever you cast a spell of the chosen type, draw a card.

Patriarch's Bidding

Each player chooses a creature type. Each player returns all creature cards of a type chosen this way from their graveyard to the battlefield.

Kindred Dominance

Choose a creature type. Destroy all creatures that aren't of the chosen type.

The Darkness Crystal

Black spells you cast cost {1} less to cast.
If a nontoken creature an opponent controls would die, instead exile it and you gain 2 life.
{4}{B}{B}, {T}: Put target creature card exiled with The Darkness Crystal onto the battlefield tapped under your control with two additional +1/+1 counters on it.

Vampiric Tutor

Search your library for a card, then shuffle and put that card on top. You lose 2 life.

Thrumming Stone

Spells you cast have ripple 4. (Whenever you cast a spell, you may reveal the top four cards of your library. You may cast spells with the same name as that spell from among the revealed cards without paying their mana costs. Put the rest on the bottom of your library.)

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.

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.

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.

Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

Corrupted Conviction

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

Echoing Return

Return target creature card and all other cards with the same name as that card from your graveyard to your hand.

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.

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.

Demonic Tutor

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

Jet Medallion

Black spells you cast cost {1} less to cast.

The Soul Stone

Indestructible
{T}: Add {B}.
{6}{B}, {T}, Exile a creature you control: Harness The Soul Stone. (Once harnessed, its ∞ ability is active.)
∞ — At the beginning of your upkeep, return target creature card from your graveyard to the battlefield.

Cover of Darkness

As this enchantment enters, choose a creature type.
Creatures of the chosen type have fear. (They can't be blocked except by artifact creatures and/or black creatures.)

Village Rites

Phyrexian Altar

Sacrifice a creature: Add one mana of any color.

Swamp

Herald's Horn

As this artifact enters, 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.

Ogre Slumlord

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

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.)

Dictate of Erebos

Flash
Whenever a creature you control dies, each opponent sacrifices a creature of their choice.