Cabal Stronghold

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

Tendrils of Corruption

Tendrils of Corruption deals X damage to target creature and you gain X life, where X is the number of Swamps you control.

Nightmare Lash

Equipped creature gets +1/+1 for each Swamp you control.
Equip—Pay 3 life. (Pay 3 life: Attach to target creature you control. Equip only as a sorcery. This card enters unattached and stays on the battlefield if the creature leaves.)

Underground Mortuary

({T}: Add {B} or {G}.)
This land enters tapped.
When this land enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Rocky Tar Pit

This land enters tapped.
{T}, Sacrifice this land: Search your library for a Swamp or Mountain card, put it onto the battlefield, then shuffle.

Woodland Chasm

({T}: Add {B} or {G}.)
This land enters tapped.

Bubbling Muck

Until end of turn, whenever a player taps a Swamp for mana, that player adds an additional {B}.

Coffin Puppets

Sacrifice two lands: Return this card from your graveyard to the battlefield. Activate only during your upkeep and only if you control a Swamp.

Blanket of Night

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

Necroblossom Snarl

As this land enters, you may reveal a Swamp or Forest card from your hand. If you don't, this land enters tapped.
{T}: Add {B} or {G}.

Staff of the Death Magus

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

Polluted Delta

{T}, Pay 1 life, Sacrifice this land: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Krosan Constrictor

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
{T}: Target black creature gets -2/-0 until end of turn.

Tainted Wood

{T}: Add {C}.
{T}: Add {B} or {G}. Activate only if you control a Swamp.

Corpse Harvester

{1}{B}, {T}, Sacrifice a creature: Search your library for a Zombie card and a Swamp card, reveal them, put them into your hand, then shuffle.

Sima Yi, Wei Field Marshal

Sima Yi's power is equal to the number of Swamps you control.

Swamp Mosquito

Flying
Whenever this creature attacks and isn't blocked, defending player gets a poison counter. (A player with ten or more poison counters loses the game.)

Fendeep Summoner

{T}: Up to two target Swamps each become 3/5 Treefolk Warrior creatures in addition to their other types until end of turn.

Evil Presence

Bayou

Bad River

This land enters tapped.
{T}, Sacrifice this land: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Sheoldred, Whispering One

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
At the beginning of your upkeep, return target creature card from your graveyard to the battlefield.
At the beginning of each opponent's upkeep, that player sacrifices a creature of their choice.

Defile

Target creature gets -1/-1 until end of turn for each Swamp you control.

Haunted Mire

Woodland Cemetery

This land enters tapped unless you control a Swamp or a Forest.
{T}: Add {B} or {G}.

Riveteers Overlook

When this land enters, sacrifice it. When you do, search your library for a basic Swamp, Mountain, or Forest card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Mutilate

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

Kormus Bell

All Swamps are 1/1 black creatures that are still lands.

Contaminated Ground

Enchant land
Enchanted land is a Swamp.
Whenever enchanted land becomes tapped, its controller loses 2 life.

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.

Cabal Coffers

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

Dread Presence

Whenever a Swamp you control enters, choose one —
• You draw a card and you lose 1 life.
• This creature deals 2 damage to any target and you gain 2 life.

Horobi's Whisper

If you control a Swamp, destroy target nonblack creature.
Splice onto Arcane—Exile four cards from your graveyard. (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

Cyclopean Tomb

{2}, {T}: Put a mire counter on target non-Swamp land. That land is a Swamp for as long as it has a mire counter on it. Activate only during your upkeep.
When this artifact is put into a graveyard from the battlefield, at the beginning of each of your upkeeps for the rest of the game, remove all mire counters from a land that a mire counter was put onto with this artifact but that a mire counter has not been removed from with this artifact.

Bog Serpent

This creature can't attack unless defending player controls a Swamp.
When you control no Swamps, sacrifice this creature.

Troll of Khazad-dûm

This creature can't be blocked except by three or more creatures.
Swampcycling {1} ({1}, Discard this card: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.)

Castle Locthwain

This land enters tapped unless you control a Swamp.
{T}: Add {B}.
{1}{B}{B}, {T}: Draw a card, then you lose life equal to the number of cards in your hand.

Corrupt

Corrupt deals damage to any target equal to the number of Swamps you control. You gain life equal to the damage dealt this way.

Urborg, Tomb of Yawgmoth

Mind Sludge

Target player discards a card for each Swamp you control.

Overgrown Tomb

({T}: Add {B} or {G}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Genju of the Fens

Enchant Swamp
{2}: Until end of turn, enchanted Swamp becomes a 2/2 black Spirit creature with "{B}: This creature gets +1/+1 until end of turn." It's still a land.
When enchanted Swamp is put into a graveyard, you may return this card from your graveyard to your hand.

Twisted Abomination

{B}: Regenerate this creature. (The next time this creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)
Swampcycling {2} ({2}, Discard this card: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.)

Gangrenous Zombies

{T}, Sacrifice this creature: This creature deals 1 damage to each creature and each player. If you control a snow Swamp, this creature deals 2 damage to each creature and each player instead.

Nightmare

Flying (This creature can't be blocked except by creatures with flying or reach.)
Nightmare's power and toughness are each equal to the number of Swamps you control.

Hecatomb

When this enchantment enters, sacrifice this enchantment unless you sacrifice four creatures.
Tap an untapped Swamp you control: This enchantment deals 1 damage to any target.

Bloodstained Mire

{T}, Pay 1 life, Sacrifice this land: Search your library for a Swamp or Mountain card, put it onto the battlefield, then shuffle.

Lashwrithe

Living weapon (When this Equipment enters, create a 0/0 black Phyrexian Germ creature token, then attach this to it.)
Equipped creature gets +1/+1 for each Swamp you control.
Equip {B/P}{B/P} ({B/P} can be paid with either {B} or 2 life.)

Veilborn Ghoul

This creature can't block.
Whenever a Swamp you control enters, you may return this card from your graveyard to your hand.

Street Wraith

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
Cycling—Pay 2 life. (Pay 2 life, Discard this card: Draw a card.)

Korlash, Heir to Blackblade

Korlash's power and toughness are each equal to the number of Swamps you control.
{1}{B}: Regenerate Korlash.
Grandeur — Discard another card named Korlash, Heir to Blackblade: Search your library for up to two Swamp cards, put them onto the battlefield tapped, then shuffle.

Zombie Trailblazer

Tap an untapped Zombie you control: Target land becomes a Swamp until end of turn.
Tap an untapped Zombie you control: Target creature gains swampwalk until end of turn. (It can't be blocked as long as defending player controls a Swamp.)

Snuff Out

If you control a Swamp, you may pay 4 life rather than pay this spell's mana cost.
Destroy target nonblack creature. It can't be regenerated.

Consuming Corruption

Consuming Corruption deals X damage to target creature or planeswalker and you gain X life, where X is the number of Swamps you control.

Snow-Covered Swamp

Magus of the Coffers

Guul Draz Overseer

Flying
Landfall — Whenever a land you control enters, other creatures you control get +1/+0 until end of turn. If that land is a Swamp, those creatures get +2/+0 until end of turn instead.

Squelching Leeches

Squelching Leeches's power and toughness are each equal to the number of Swamps you control.

Spymaster's Vault

This land enters tapped unless you control a Swamp.
{T}: Add {B}.
{B}, {T}: Target creature you control connives X, where X is the number of creatures that died this turn. (Draw X cards, then discard X cards. Put a +1/+1 counter on that creature for each nonland card discarded this way.)

This creature gets +0/+2 as long as you control a Plains, has flying as long as you control an Island, gets +2/+0 as long as you control a Swamp, has first strike as long as you control a Mountain, and has trample as long as you control a Forest.

Witch's Cottage

({T}: Add {B}.)
This land enters tapped unless you control three or more other Swamps.
When this land enters untapped, you may put target creature card from your graveyard on top of your library.

Dakmor Sorceress

Dakmor Sorceress's power is equal to the number of Swamps you control.

Zombie Master

Other Zombie creatures have swampwalk. (They can't be blocked as long as defending player controls a Swamp.)
Other Zombies have "{B}: Regenerate this permanent."

Odylic Wraith

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
Whenever this creature deals damage to a player, that player discards a card.

Sewerdreg

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
Sacrifice this creature: Exile target card from a graveyard.

Wormwood Treefolk

{G}{G}: This creature gains forestwalk until end of turn and deals 2 damage to you. (It can't be blocked as long as defending player controls a Forest.)
{B}{B}: This creature gains swampwalk until end of turn and deals 2 damage to you. (It can't be blocked as long as defending player controls a Swamp.)

Verdant Catacombs

{T}, Pay 1 life, Sacrifice this land: Search your library for a Swamp or Forest card, put it onto the battlefield, then shuffle.

Tainted Well

Enchant land
When this Aura enters, draw a card.
Enchanted land is a Swamp.

Nirkana Revenant

Whenever you tap a Swamp for mana, add an additional {B}.
{B}: This creature gets +1/+1 until end of turn.

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}.

Mire Shade

{B}, Sacrifice a Swamp: Put a +1/+1 counter on this creature. Activate only as a sorcery.

Jarad, Golgari Lich Lord

Jarad gets +1/+1 for each creature card in your graveyard.
{1}{B}{G}, Sacrifice another creature: Each opponent loses life equal to the sacrificed creature's power.
Sacrifice a Swamp and a Forest: Return this card from your graveyard to your hand.

Horror of Horrors

Sacrifice a Swamp: Regenerate target black creature. (The next time that creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Liliana of the Dark Realms

+1: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.
−3: Target creature gets +X/+X or -X/-X until end of turn, where X is the number of Swamps you control.
−6: You get an emblem with "Swamps you control have '{T}: Add {B}{B}{B}{B}.'"

Strands of Night

{B}{B}, Pay 2 life, Sacrifice a Swamp: Return target creature card from your graveyard to the battlefield.

Leechridden Swamp

({T}: Add {B}.)
This land enters tapped.
{B}, {T}: Each opponent loses 1 life. Activate only if you control two or more black permanents.

Cyclopean Giant

When this creature dies, target land becomes a Swamp. Exile this creature.

Massacre

If an opponent controls a Plains and you control a Swamp, you may cast this spell without paying its mana cost.
All creatures get -2/-2 until end of turn.

Quag Sickness

Enchant creature
Enchanted creature gets -1/-1 for each Swamp you control.

Withering Wisps

At the beginning of the end step, if no creatures are on the battlefield, sacrifice this enchantment.
{B}: This enchantment deals 1 damage to each creature and each player. Activate no more times each turn than the number of snow Swamps you control.

Whispering Shade

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
{B}: This creature gets +1/+1 until end of turn.

Swamp

Nightcreep

Until end of turn, all creatures become black and all lands become Swamps.

Liliana's Shade

When this creature enters, you may search your library for a Swamp card, reveal it, put it into your hand, then shuffle.
{B}: This creature gets +1/+1 until end of turn.

Wormwood Dryad

{G}: This creature gains forestwalk until end of turn and deals 1 damage to you. (It can't be blocked as long as defending player controls a Forest.)
{B}: This creature gains swampwalk until end of turn and deals 1 damage to you. (It can't be blocked as long as defending player controls a Swamp.)

Viscid Lemures

{0}: This creature gets -1/-0 and gains swampwalk until end of turn. (It can't be blocked as long as defending player controls a Swamp.)

Deepwood Legate

If an opponent controls a Forest and you control a Swamp, you may cast this spell without paying its mana cost.
{B}: This creature gets +1/+1 until end of turn.

Marsh Lurker

Sacrifice a Swamp: This creature gains fear until end of turn. (It can't be blocked except by artifact creatures and/or black creatures.)

Dross Golem

Affinity for Swamps (This spell costs {1} less to cast for each Swamp you control.)
Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)

Choking Sands

Destroy target non-Swamp land. If that land was nonbasic, Choking Sands deals 2 damage to the land's controller.

Jund Panorama

{T}: Add {C}.
{1}, {T}, Sacrifice this land: Search your library for a basic Swamp, Mountain, or Forest card, put it onto the battlefield tapped, then shuffle.

Marsh Flats

{T}, Pay 1 life, Sacrifice this land: Search your library for a Plains or Swamp card, put it onto the battlefield, then shuffle.