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.

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.

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

{T}: Add {C}.

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

When Chittering Witch 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.

Black creatures you control have wither. (They deal damage to creatures in the form of -1/-1 counters.)

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}.

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

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

Add {B}{B}{B}{B}.

Add {B}{B}{B}.

Return X target creature cards from your graveyard to your hand.

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

Flash

Whenever a creature you control dies, each opponent sacrifices a creature.

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.

Creatures you control get +1/+1 and have flying and indestructible.

At the beginning of your upkeep, sacrifice a creature. If you can't, sacrifice Eldrazi Monument.

Enchant creature

Endless Scream enters with X scream counters on it.

Enchanted creature gets +1/+0 for each scream counter on Endless Scream.

Each opponent loses X life. You gain life equal to the life lost this way.

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

At the beginning of combat on your turn, if you both own and control Graf Rats and a creature named Midnight Scavengers, exile them, then meld them into Chittering Host.

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.)

Each opponent loses 1 life for each creature you control.

At the beginning of combat on your turn, create a token that's a copy of equipped creature, except the token isn't legendary. That token gains haste.

Equip {5}

Destroy target creature or planeswalker.

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

When Ichor Rats enters the battlefield, each player gets a poison counter.

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

Ninjutsu {3}{B}{B} ({3}{B}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)

Whenever Ink-Eyes, Servant of Oni deals combat damage to a player, you may put target creature card from that player's graveyard onto the battlefield under your control.

{1}{B}: Regenerate Ink-Eyes.

At the beginning of your upkeep, sacrifice Koskun Falls unless you tap an untapped creature you control.

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

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.

When Midnight Scavengers enters the battlefield, you may return target creature card with mana value 3 or less from your graveyard to your hand.

(Melds with Graf Rats.)

{2}: Mirage Mirror becomes a copy of target artifact, creature, enchantment, or land until end of turn.

Destroy target creature.

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

Rats you control have deathtouch.

Ninjutsu {3}{B} ({3}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)

Whenever Okiba-Gang Shinobi deals combat damage to a player, that player discards two cards.

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.

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.)

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

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.

Destroy all creatures you don't control. They can't be regenerated.

Equipped creature has deathtouch.

Whenever equipped creature deals combat damage to a player, that player loses half their life, rounded up.

Equip {3}

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.)

Rat Colony gets +1/+0 for each other Rat you control.

A deck can have any number of cards named Rat Colony.

Rat Colony gets +1/+0 for each other Rat you control.

A deck can have any number of cards named Rat Colony.

Rat Colony gets +1/+0 for each other Rat you control.

A deck can have any number of cards named Rat Colony.

Rat Colony gets +1/+0 for each other Rat you control.

A deck can have any number of cards named Rat Colony.

Rat Colony gets +1/+0 for each other Rat you control.

A deck can have any number of cards named Rat Colony.

Rat Colony gets +1/+0 for each other Rat you control.

A deck can have any number of cards named Rat Colony.

Rat Colony gets +1/+0 for each other Rat you control.

A deck can have any number of cards named Rat Colony.

Rat Colony gets +1/+0 for each other Rat you control.

A deck can have any number of cards named Rat Colony.

Rat Colony gets +1/+0 for each other Rat you control.

A deck can have any number of cards named Rat Colony.

Rat Colony gets +1/+0 for each other Rat you control.

A deck can have any number of cards named Rat Colony.

Rat Colony gets +1/+0 for each other Rat you control.

A deck can have any number of cards named Rat Colony.

Rat Colony gets +1/+0 for each other Rat you control.

A deck can have any number of cards named Rat Colony.

Rat Colony gets +1/+0 for each other Rat you control.

A deck can have any number of cards named Rat Colony.

Rat Colony gets +1/+0 for each other Rat you control.

A deck can have any number of cards named Rat Colony.

Rat Colony gets +1/+0 for each other Rat you control.

A deck can have any number of cards named Rat Colony.

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.

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

You have no maximum hand size.

{T}: Add {C}.

Deathtouch

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

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.

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)

Until end of turn, creatures target player controls lose all abilities and have base power and toughness 0/2.

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

{T}: Add {C}.

{T}: Regenerate target Insect, Rat, Spider, or Squirrel. (The next time it would be destroyed, instead tap it, remove it from combat, and heal all damage on it.)

Equipped creature has "{2}, {T}: This creature deals 1 damage to any target" and "Whenever a creature dies, untap this creature."

Whenever a Shaman creature enters, you may attach Thornbite Staff to it.

Equip {4}

At the beginning of your end step, each opponent loses life equal to the number of tapped creatures you control.

Target creature gets -1/-1 until end of turn.

Morbid -- That creature gets -13/-13 until end of turn instead if a creature died this turn.

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

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.

{T}: Add {C}.

{5}, {T}, Pay 1 life: Create a 1/1 white and black Human Cleric creature token.

{5}, {T}, Sacrifice five creatures: Transform Westvale Abbey, then untap it.

Flying, lifelink, indestructible, haste

Creatures you control have lifelink.

{2}{B}{B}, {T}: Return target creature card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step. If it would leave the battlefield, exile it instead of putting it anywhere else. Activate only as a sorcery.