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.)

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.

As Icon of Ancestry enters the battlefield, choose a creature type. Creatures you control of the chosen type get +1/+1. {3}, {T}: Look at the top three cards of your library. You may reveal a creature card of the chosen type from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

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

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

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

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

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.

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."

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.

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.

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

As Species Specialist enters the battlefield, choose a creature type. Whenever a creature of the chosen type dies, you may draw a card.

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.

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.

Whenever Blood Artist or another creature dies, target player loses 1 life and you gain 1 life.

When Gray Merchant of Asphodel enters the battlefield, 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.)

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

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 artifact: Add one mana of any color.")

Whenever a Swamp enters the battlefield under your control, choose one — • You draw a card and you lose 1 life. • Dread Presence deals 2 damage to any target and you gain 2 life.

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.) Other Rats you control have toxic 1. When Karumonix enters the battlefield, 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.

Whenever one or more other creatures die, draw a card. This ability triggers only once each turn.

Enchant creature Enchanted creature has "Whenever another creature dies, put a +1/+1 counter on this creature." When enchanted creature dies, look at the top X cards of your library, where X is its power. Put one of those cards into your hand and the rest on the bottom of your library in a random order.

At the beginning of your upkeep, if you have four or more creature cards in your graveyard, you may return target creature card from your graveyard to your hand.

Choose one — • Return target creature card from your graveyard to your hand. • Return two target creature cards that share a creature type from your graveyard to your hand.

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."

{T}: Add {C}. {2}, {T}: Add X mana of any one color, where X is the number of other Gates you control.

Barren Moor enters the battlefield tapped. {T}: Add {B}. Cycling {B} ({B}, Discard this card: Draw a card.)

{T}: Add {C}. {2}, {T}: Target creature gets +X/+X until end of turn, where X is the number of Gates you control. Activate only as a sorcery.

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

{T}: Add {C}. {3}, {T}: Add {B} for each basic Swamp you control.

As Cavern of Souls enters the battlefield, choose a creature type. {T}: Add {C}. {T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

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

Diamond City enters the battlefield with a shield counter on it. (If it would be dealt damage or destroyed, remove a shield counter from it instead.) {T}: Add {C}. {T}: Move a shield counter from Diamond City onto target creature. Activate only if two or more creatures entered the battlefield under your control this turn.

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

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

Whenever a creature dies, put a charge counter on Black Market. At the beginning of your precombat main phase, add {B} for each charge counter on Black Market.

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.) Whenever you tap a Swamp for mana, add an additional {B}.

Add {B}{B}{B}.

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

Whenever Ashcoat of the Shadow Swarm 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.)

Destroy target nonblack creature. It can't be regenerated. Draw a card.

You may pay {1}{B} rather than pay this spell's mana cost. If the {1}{B} cost was paid, an opponent draws a card. Exile target creature or planeswalker.

Destroy all creatures. They can't be regenerated.

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

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

When Plaguecrafter enters the battlefield, each player sacrifices a creature or planeswalker. Each player who can't discards a card.

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

Each opponent loses 1 life for each creature you control.

Destroy all creatures you don't control and all planeswalkers you don't control.

Buyback {4} (You may pay an additional {4} as you cast this spell. If you do, put this card into your hand as it resolves.) Create a 1/1 black Rat creature token.

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

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