Swamp

Mercenary Knight

When Mercenary Knight enters the battlefield, sacrifice it unless you discard a creature card.

Hedron Archive

{T}: Add {C}{C}.
{2}, {T}, Sacrifice Hedron Archive: Draw two cards.

Crown of Suspicion

Enchant creature
Enchanted creature gets +2/-1.
Sacrifice Crown of Suspicion: Enchanted creature and other creatures that share a creature type with it get +2/-1 until end of turn.

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.

Dark Ritual

Dauthi Mercenary

Shadow (This creature can block or be blocked by only creatures with shadow.)
{1}{B}: Dauthi Mercenary gets +1/+0 until end of turn.

Doom Cannon

As Doom Cannon enters the battlefield, choose a creature type.
{3}, {T}, Sacrifice a creature of the chosen type: Doom Cannon deals 3 damage to any target.

Cateran Kidnappers

{3}, {T}: Search your library for a Mercenary permanent card with mana value 3 or less, put it onto the battlefield, then shuffle.

Cateran Slaver

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
{5}, {T}: Search your library for a Mercenary permanent card with mana value 5 or less, put it onto the battlefield, then shuffle.

Mirror of the Forebears

As Mirror of the Forebears enters the battlefield, choose a creature type.
{1}: Until end of turn, Mirror of the Forebears becomes a copy of target creature you control of the chosen type, except it's an artifact in addition to its other types.

Doomed Necromancer

{B}, {T}, Sacrifice Doomed Necromancer: Return target creature card from your graveyard to the battlefield.

Pillar of Origins

As Pillar of Origins enters the battlefield, choose a creature type.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type.

Proteus Machine

Morph {0} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When Proteus Machine is turned face up, it becomes the creature type of your choice. (This effect lasts indefinitely.)

Dark Triumph

If you control a Swamp, you may sacrifice a creature rather than pay this spell's mana cost.
Creatures you control get +2/+0 until end of turn.

Primeval Shambler

{B}: Primeval Shambler gets +1/+1 until end of turn.

Icon of Ancestry

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.

Cateran Summons

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

Aphetto Dredging

Return up to three target creature cards of the creature type of your choice from your graveyard to your hand.

Skeletal Changeling

Changeling (This card is every creature type.)
{1}{B}: Regenerate Skeletal Changeling.

Silent Assassin

{3}{B}: Destroy target blocking creature at end of combat.

Pit Raptor

Flying, first strike
At the beginning of your upkeep, sacrifice Pit Raptor unless you pay {2}{B}{B}.

Phyrexian Prowler

Fading 3 (This creature enters the battlefield with three fade counters on it. At the beginning of your upkeep, remove a fade counter from it. If you can't, sacrifice it.)
Remove a fade counter from Phyrexian Prowler: Phyrexian Prowler gets +1/+1 until end of turn.

Phyrexian Driver

When Phyrexian Driver enters the battlefield, other Mercenary creatures get +1/+1 until end of turn.

Mind Stone

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

Mercadian Atlas

At the beginning of your end step, if you didn't play a land this turn, you may draw a card.

Diabolic Tutor

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

Goblin Turncoat

Sacrifice a Goblin: Regenerate Goblin Turncoat.

Rebel Informer

Rebel Informer can't be the target of white spells or abilities from white sources.
{3}: Put target nontoken Rebel on the bottom of its owner's library.

Rathi Intimidator

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
{2}, {T}: Search your library for a Mercenary permanent card with mana value 2 or less, put it onto the battlefield, then shuffle.

Strongarm Thug

When Strongarm Thug enters the battlefield, you may return target Mercenary card from your graveyard to your hand.

Mutilate

All creatures get -1/-1 until end of turn for each Swamp you control.

Ascendant Evincar

Flying (This creature can't be blocked except by creatures with flying or reach.)
Other black creatures get +1/+1.
Nonblack creatures get -1/-1.

Rampart Crawler

Rampart Crawler can't be blocked by Walls.

Skulking Fugitive

When Skulking Fugitive becomes the target of a spell or ability, sacrifice it.

Alley Grifters

Whenever Alley Grifters becomes blocked, defending player discards a card.

Cateran Enforcer

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
{4}, {T}: Search your library for a Mercenary permanent card with mana value 4 or less, put it onto the battlefield, then shuffle.

Highway Robber

When Highway Robber enters the battlefield, target opponent loses 2 life and you gain 2 life.

Cateran Overlord

Sacrifice a creature: Regenerate Cateran Overlord.
{6}, {T}: Search your library for a Mercenary permanent card with mana value 6 or less, put it onto the battlefield, then shuffle.

Charcoal Diamond

Charcoal Diamond enters the battlefield tapped.
{T}: Add {B}.

Rathi Assassin

{1}{B}{B}, {T}: Destroy target tapped nonblack creature.
{3}, {T}: Search your library for a Mercenary permanent card with mana value 3 or less, put it onto the battlefield, then shuffle.

Stoneforge Masterwork

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

Bog Smugglers

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

Worn Powerstone

Worn Powerstone enters the battlefield tapped.
{T}: Add {C}{C}.

Spineless Thug

Misshapen Fiend

K'rrik, Son of Yawgmoth

({B/P} can be paid with either {B} or 2 life.)
Lifelink
For each {B} in a cost, you may pay 2 life rather than pay that mana.
Whenever you cast a black spell, put a +1/+1 counter on K'rrik, Son of Yawgmoth.

Death Charmer

Whenever Death Charmer deals combat damage to a creature, that creature's controller loses 2 life unless they pay {2}.

Rathi Fiend

When Rathi Fiend enters the battlefield, each player loses 3 life.
{3}, {T}: Search your library for a Mercenary permanent card with mana value 3 or less, put it onto the battlefield, then shuffle.

Cateran Brute

{2}, {T}: Search your library for a Mercenary permanent card with mana value 2 or less, put it onto the battlefield, then shuffle.

Cateran Persuader

{1}, {T}: Search your library for a Mercenary permanent card with mana value 1 or less, put it onto the battlefield, then shuffle.

Agent of Shauku

{1}{B}, Sacrifice a land: Target creature gets +2/+0 until end of turn.

Molting Harpy

Flying
At the beginning of your upkeep, sacrifice Molting Harpy unless you pay {2}.

Bog Glider

Flying
{T}, Sacrifice a land: Search your library for a Mercenary permanent card with mana value 2 or less, put it onto the battlefield, then shuffle.

Spiteful Bully

At the beginning of your upkeep, Spiteful Bully deals 3 damage to target creature you control.

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.

Sol Ring

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.

Heartstone

Activated abilities of creatures cost {1} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Well of Discovery

At the beginning of your end step, if you control no untapped lands, draw a card.

Graveshifter

Changeling (This card is every creature type.)
When Graveshifter enters the battlefield, you may return target creature card from your graveyard to your hand.

Skull of Ramos

{T}: Add {B}.
Sacrifice Skull of Ramos: Add {B}.

Living Death

Each player exiles all creature cards from their graveyard, then sacrifices all creatures they control, then puts all cards they exiled this way onto the battlefield.

Extinction

Destroy all creatures of the creature type of your choice.

Universal Automaton

Changeling (This card is every creature type.)

Pack's Disdain

Choose a creature type. Target creature gets -1/-1 until end of turn for each permanent of the chosen type you control.