Mausoleum Secrets

Undergrowth — Search your library for a black card with mana value less than or equal to the number of creature cards in your graveyard, reveal it, put it into your hand, then shuffle.

Force of Despair

If it's not your turn, you may exile a black card from your hand rather than pay this spell's mana cost.
Destroy all creatures that entered this turn.

Go for the Throat

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.

Ravenous Rats

When Ravenous Rats enters, target opponent discards a card.

Plague Rats

Plague Rats's power and toughness are each equal to the number of creatures named Plague Rats on the battlefield.

Call of the Death-Dweller

Return up to two target creature cards with total mana value 3 or less from your graveyard to the battlefield. Put a deathtouch counter on either of them. Then put a menace counter on either of them.

Cabal Coffers

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

Chainer's Edict

Target player sacrifices a creature of their choice.
Flashback {5}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Eliminate

Destroy target creature or planeswalker with mana value 3 or less.

Duress

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.

Nyx Lotus

Nyx Lotus enters tapped.
{T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

Crypt Rats

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

Murder

Soul Shatter

Each opponent sacrifices a creature or planeswalker with the highest mana value among creatures and planeswalkers they control.

Songs of the Damned

Add {B} for each creature card in your graveyard.

Omen of the Dead

Flash
When Omen of the Dead enters, return target creature card from your graveyard to your hand.
{2}{B}, Sacrifice Omen of the Dead: Scry 2.

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.

Rat Colony

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

Mikaeus, the Unhallowed

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
Whenever a Human deals damage to you, destroy it.
Other non-Human creatures you control get +1/+1 and have undying. (When a creature with undying dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Herald's Horn

As Herald's Horn 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.

Lantern of Insight

Players play with the top card of their libraries revealed.
{T}, Sacrifice Lantern of Insight: Target player shuffles.

Ruin Rat

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

Diabolic Tutor

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

Macabre Waltz

Return up to two target creature cards from your graveyard to your hand, then discard a card.

Raise Dead

Return target creature card from your graveyard to your hand.

Font of Agonies

Whenever you pay life, put that many blood counters on Font of Agonies.
{1}{B}, Remove four blood counters from Font of Agonies: Destroy target creature.

Caged Sun

As Caged Sun 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 one additional mana of that color.

Drainpipe Vermin

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

Ogre Slumlord

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

Vicious Rumors

Vicious Rumors deals 1 damage to each opponent. Each opponent discards a card, then mills a card. You gain 1 life.

Sanguine Bond

Whenever you gain life, target opponent loses that much life.

Bankrupt in Blood

As an additional cost to cast this spell, sacrifice two creatures.
Draw three cards.

Swarm of Rats

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

Chittering Witch

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.

Staff of the Death Magus

Whenever you cast a black spell or a Swamp you control enters, you gain 1 life.

Nezumi Cutthroat

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

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Exquisite Blood

Whenever an opponent loses life, you gain that much life.

Plaguecrafter

When Plaguecrafter enters, each player sacrifices a creature or planeswalker of their choice. Each player who can't discards a card.

Heraldic Banner

As this artifact enters, choose a color.
Creatures you control of the chosen color get +1/+0.
{T}: Add one mana of the chosen color.

Crypt Ghast

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}.

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.)

Beseech the Queen

({2/B} can be paid with any two mana or with {B}. This card's mana value is 6.)
Search your library for a card with mana value less than or equal to the number of lands you control, reveal it, put it into your hand, then shuffle.

Burglar Rat

When this creature enters, each opponent discards 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.)

Magus of the Coffers

Swamp

Runed Servitor

When Runed Servitor dies, each player draws a card.

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.

Typhoid Rats

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

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.

Bojuka Bog

Bojuka Bog enters tapped.
When Bojuka Bog enters, exile target player's graveyard.
{T}: Add {B}.

Malicious Affliction

Morbid — When you cast this spell, if a creature died this turn, you may copy Malicious Affliction and may choose a new target for the copy.
Destroy target nonblack creature.