Urborg, Tomb of Yawgmoth

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

Sol Ring

Tainted Wood

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

Grisly Salvage

Reveal the top five cards of your library. You may put a creature or land card from among them into your hand. Put the rest into your graveyard.

Fertilid

This creature enters with two +1/+1 counters on it.
{1}{G}, Remove a +1/+1 counter from this creature: Target player searches their library for a basic land card, puts it onto the battlefield tapped, then shuffles.

Evolution Sage

Landfall — Whenever a land you control enters, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Fabled Passage

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Then if you control four or more lands, untap that land.

Bojuka Bog

This land enters tapped.
When this land enters, exile target player's graveyard.
{T}: Add {B}.

Polukranos, Unchained

Polukranos enters with six +1/+1 counters on it. It escapes with twelve +1/+1 counters on it instead.
If damage would be dealt to Polukranos while it has a +1/+1 counter on it, prevent that damage and remove that many +1/+1 counters from it.
{1}{B}{G}: Polukranos fights another target creature.
Escape—{4}{B}{G}, Exile six other cards from your graveyard.

Command Tower

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

Deathsprout

Destroy target creature. Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

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.

Windswept Heath

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

Vigor

Trample
If damage would be dealt to another creature you control, prevent that damage. Put a +1/+1 counter on that creature for each 1 damage prevented this way.
When Vigor is put into a graveyard from anywhere, shuffle it into its owner's library.

Rishkar's Expertise

Draw cards equal to the greatest power among creatures you control.
You may cast a spell with mana value 5 or less from your hand without paying its mana cost.

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.

Soul's Majesty

Draw cards equal to the power of target creature you control.

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.

Crowned Ceratok

Trample
Each creature you control with a +1/+1 counter on it has trample.

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Satyr Wayfinder

When this creature enters, reveal the top four cards of your library. You may put a land card from among them into your hand. Put the rest into your graveyard.

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.

Relentless Pursuit

Reveal the top four cards of your library. You may put a creature card and/or a land card from among them into your hand. Put the rest into your graveyard.

Ordeal of Nylea

Enchant creature
Whenever enchanted creature attacks, put a +1/+1 counter on it. Then if it has three or more +1/+1 counters on it, sacrifice this Aura.
When you sacrifice this Aura, search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Necropolis Regent

Flying
Whenever a creature you control deals combat damage to a player, put that many +1/+1 counters on it.

Woodland Cemetery

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

Casualties of War

Choose one or more —
• Destroy target artifact.
• Destroy target creature.
• Destroy target enchantment.
• Destroy target land.
• Destroy target planeswalker.

Lotus Field

Hexproof
This land enters tapped.
When this land enters, sacrifice two lands.
{T}: Add three mana of any one color.

Windgrace's Judgment

For any number of opponents, destroy target nonland permanent that player controls.

Winding Way

Choose creature or land. Reveal the top four cards of your library. Put all cards of the chosen type revealed this way into your hand and the rest into your graveyard.

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.

Sakura-Tribe Elder

Sacrifice this creature: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Prismatic Vista

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

Llanowar Wastes

{T}: Add {C}.
{T}: Add {B} or {G}. This land deals 1 damage to you.

Expedition Map

{2}, {T}, Sacrifice this artifact: Search your library for a land card, reveal it, put it into your hand, then shuffle.

Nurturing Peatland

{T}, Pay 1 life: Add {B} or {G}.
{1}, {T}, Sacrifice this land: Draw a card.

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.

Tuskguard Captain

Outlast {G} ({G}, {T}: Put a +1/+1 counter on this creature. Outlast only as a sorcery.)
Each creature you control with a +1/+1 counter on it has trample.

The First Iroan Games

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after IV.)
I — Create a 1/1 white Human Soldier creature token.
II — Put three +1/+1 counters on target creature you control.
III — If you control a creature with power 4 or greater, draw two cards.
IV — Create a Gold token. (It's an artifact with "Sacrifice this token: Add one mana of any color.")

Eternal Witness

When this creature enters, you may return target card from your graveyard to your hand.

Mulch

Reveal the top four cards of your library. Put all land cards revealed this way into your hand and the rest into your graveyard.

Pir, Imaginative Rascal

Partner with Toothy, Imaginary Friend (When this creature enters, target player may put Toothy into their hand from their library, then shuffle.)
If one or more counters would be put on a permanent your team controls, that many plus one of each of those kinds of counters are put on that permanent instead.

The Great Henge

This spell costs {X} less to cast, where X is the greatest power among creatures you control.
{T}: Add {G}{G}. You gain 2 life.
Whenever a nontoken creature you control enters, put a +1/+1 counter on it and draw a card.

Springbloom Druid

When this creature enters, you may sacrifice a land. If you do, search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Vulturous Zombie

Flying
Whenever a card is put into an opponent's graveyard from anywhere, put a +1/+1 counter on this creature.

Nature's Claim

Destroy target artifact or enchantment. Its controller gains 4 life.

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.

Into the North

Search your library for a snow land card, put it onto the battlefield tapped, then shuffle.

Ash Barrens

{T}: Add {C}.
Basic landcycling {1} ({1}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Greater Good

Sacrifice a creature: Draw cards equal to the sacrificed creature's power, then discard three cards.

Assassin's Trophy

Destroy target permanent an opponent controls. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

Corpsejack Menace

If one or more +1/+1 counters would be put on a creature you control, twice that many +1/+1 counters are put on it instead.

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

Misty Rainforest

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

Harmonize

Inspiring Call

Draw a card for each creature you control with a +1/+1 counter on it. Those creatures gain indestructible until end of turn. (Damage and effects that say "destroy" don't destroy them.)

Death's Presence

Whenever a creature you control dies, put X +1/+1 counters on target creature you control, where X is the power of the creature that died.

Brawn

Trample
As long as this card is in your graveyard and you control a Forest, creatures you control have trample.

Skyshroud Claim

Search your library for up to two Forest cards, put them onto the battlefield, then shuffle.

Barren Moor

This land enters tapped.
{T}: Add {B}.
Cycling {B} ({B}, Discard this card: Draw a card.)

Crashing Drawbridge

Defender
{T}: Creatures you control gain haste until end of turn.

Garruk, Primal Hunter

+1: Create a 3/3 green Beast creature token.
−3: Draw cards equal to the greatest power among creatures you control.
−6: Create a 6/6 green Wurm creature token for each land you control.

Corpse Churn

Mill three cards, then you may return a creature card from your graveyard to your hand. (To mill three cards, put the top three cards of your library into your graveyard.)

Snow-Covered Forest

Momentous Fall

As an additional cost to cast this spell, sacrifice a creature.
You draw cards equal to the sacrificed creature's power, then you gain life equal to its toughness.

Hardened Scales

If one or more +1/+1 counters would be put on a creature you control, that many plus one +1/+1 counters are put on it instead.

Forgotten Ancient

Whenever a player casts a spell, you may put a +1/+1 counter on this creature.
At the beginning of your upkeep, you may move any number of +1/+1 counters from this creature onto other creatures.

Force of Vigor

If it's not your turn, you may exile a green card from your hand rather than pay this spell's mana cost.
Destroy up to two target artifacts and/or enchantments.

Overgrown Tomb

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

Grapple with the Past

Mill three cards, then you may return a creature or land card from your graveyard to your hand. (To mill three cards, put the top three cards of your library into your graveyard.)

Winding Constrictor

If one or more counters would be put on an artifact or creature you control, that many plus one of each of those kinds of counters are put on that permanent instead.
If you would get one or more counters, you get that many plus one of each of those kinds of counters instead.

Putrefy

Destroy target artifact or creature. It can't be regenerated.

Ransack the Lab

Look at the top three cards of your library. Put one of them into your hand and the rest into your graveyard.

Retreat to Kazandu

Landfall — Whenever a land you control enters, choose one —
• Put a +1/+1 counter on target creature.
• You gain 2 life.

Managorger Hydra

Trample
Whenever a player casts a spell, put a +1/+1 counter on this creature.

Wooded Foothills

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

Return of the Wildspeaker

Choose one —
• Draw cards equal to the greatest power among non-Human creatures you control.
• Non-Human creatures you control get +3/+3 until end of turn.

Acolyte of Affliction

When this creature enters, mill two cards, then you may return a permanent card from your graveyard to your hand.

Reyhan, Last of the Abzan

Reyhan enters with three +1/+1 counters on it.
Whenever a creature you control dies or is put into the command zone, if it had one or more +1/+1 counters on it, you may put that many +1/+1 counters on target creature.
Partner (You can have two commanders if both have partner.)

Cabal Coffers

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

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Elemental Bond

Whenever a creature you control with power 3 or greater enters, draw a card.

Traverse the Outlands

Search your library for up to X basic land cards, where X is the greatest power among creatures you control. Put those cards onto the battlefield tapped, then shuffle.

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Tranquil Thicket

This land enters tapped.
{T}: Add {G}.
Cycling {G} ({G}, Discard this card: Draw a card.)