Urborg, Tomb of Yawgmoth

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

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Wild-Magic Sorcerer

The first spell you cast from exile each turn has cascade. (When you cast your first spell from exile, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom of your library in a random order.)

Sea Gate, Reborn

As Sea Gate, Reborn enters the battlefield, you may pay 3 life. If you don't, it enters the battlefield tapped.
{T}: Add {U}.

Sea Gate Restoration

Draw cards equal to the number of cards in your hand plus one. You have no maximum hand size for the rest of the game.

Sea Gate Restoration // Sea Gate, Reborn

Surge Mare

Surge Mare can't be blocked by green creatures.
Whenever Surge Mare deals damage to an opponent, you may draw a card. If you do, discard a card.
{1}{U}: Surge Mare gets +2/-2 until end of turn.

Mana Confluence

{T}, Pay 1 life: Add one mana of any color.

Nephalia Academy

If a spell or ability an opponent controls causes you to discard a card, you may reveal that card and put it on top of your library instead of putting it anywhere else.
{T}: Add {C}.

Maelstrom Wanderer

Creatures you control have haste.
Cascade, cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom of your library in a random order. Then do it again.)

Vesuva

You may have Vesuva enter the battlefield tapped as a copy of any land on the battlefield.

Frost Fair Lure Fish

When Frost Fair Lure Fish enters the battlefield, create two 1/1 blue Fish creature tokens and two tapped Treasure tokens.
Fish you control have haste and can't be blocked by Humans.
Foretell {3}{U}{R}

Tyrite Sanctum

{T}: Add {C}.
{2}, {T}: Target legendary creature becomes a God in addition to its other types. Put a +1/+1 counter on it.
{4}, {T}, Sacrifice Tyrite Sanctum: Put an indestructible counter on target God.

Safe Haven

{2}, {T}: Exile target creature you control.
At the beginning of your upkeep, you may sacrifice Safe Haven. If you do, return each card exiled with Safe Haven to the battlefield under its owner's control.

Whispersilk Cloak

Equipped creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)
Equip {2}

Cloud Manta

Passionate Archaeologist

Commander creatures you own have "Whenever you cast a spell from exile, this creature deals damage equal to that spell's mana value to target opponent."

Wavebreak Hippocamp

Whenever you cast your first spell during each opponent's turn, draw a card.

Wormfang Behemoth

When Wormfang Behemoth enters the battlefield, exile all cards from your hand.
When Wormfang Behemoth leaves the battlefield, return the exiled cards to their owner's hand.

Shipwreck Moray

When Shipwreck Moray enters the battlefield, you get {E}{E}{E}{E} (four energy counters).
Pay {E}: Shipwreck Moray gets +2/-2 until end of turn.

Ancestral Vision

Suspend 4—{U} (Rather than cast this card from your hand, pay {U} and exile it with four time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)
Target player draws three cards.

Swamp

Yavimaya, Cradle of Growth

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

Azcanta, the Sunken Ruin

(Transforms from Search for Azcanta.)
{T}: Add {U}.
{2}{U}, {T}: Look at the top four cards of your library. You may reveal a noncreature, nonland card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Search for Azcanta

At the beginning of your upkeep, surveil 1. Then if you have seven or more cards in your graveyard, you may transform Search for Azcanta. (Look at the top card of your library. You may put that card into your graveyard.)

Search for Azcanta // Azcanta, the Sunken Ruin

Deepglow Skate

When Deepglow Skate enters the battlefield, double the number of each kind of counter on any number of target permanents.

Stinging Lionfish

Whenever you cast your first spell during each opponent's turn, you may tap or untap target nonland permanent.

Wormfang Manta

Flying
When Wormfang Manta enters the battlefield, you skip your next turn.
When Wormfang Manta leaves the battlefield, you take an extra turn after this one.

Tarnished Citadel

{T}: Add {C}.
{T}: Add one mana of any color. Tarnished Citadel deals 3 damage to you.

Tidal Barracuda

Any player may cast spells as though they had flash.
Your opponents can't cast spells during your turn.

Aqueous Form

Enchant creature
Enchanted creature can't be blocked.
Whenever enchanted creature attacks, scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

Nykthos, Shrine to Nyx

{T}: Add {C}.
{2}, {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.)

Dandân

Dandân can't attack unless defending player controls an Island.
When you control no Islands, sacrifice Dandân.

Spires of Orazca

(Transforms from Thaumatic Compass.)
{T}: Add {C}.
{T}: Untap target attacking creature an opponent controls and remove it from combat.

Thaumatic Compass

{3}, {T}: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.
At the beginning of your end step, if you control seven or more lands, transform Thaumatic Compass.

Thaumatic Compass // Spires of Orazca

Vivid Flying Fish

Vivid Flying Fish has flying as long as it's attacking. (It can't be blocked except by creatures with flying or reach.)

Dig Through Time

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Look at the top seven cards of your library. Put two of them into your hand and the rest on the bottom of your library in any order.

Sol Ring

Soldevi Excavations

If Soldevi Excavations would enter the battlefield, sacrifice an untapped Island instead. If you do, put Soldevi Excavations onto the battlefield. If you don't, put it into its owner's graveyard.
{T}: Add {C}{U}.
{1}, {T}: Scry 1.

Coral Eel

Sleep with the Fishes

Enchant creature
When Sleep with the Fishes enters the battlefield, tap enchanted creature and you create a 1/1 blue Fish creature token with "This creature can't be blocked."
Enchanted creature doesn't untap during its controller's untap step.

Averna, the Chaos Bloom

As you cascade, you may put a land card from among the exiled cards onto the battlefield tapped. (Do this after the last card is exiled but before deciding whether to cast a nonland card.)

Sunbird's Invocation

Whenever you cast a spell from your hand, reveal the top X cards of your library, where X is that spell's mana value. You may cast a spell with mana value X or less from among cards revealed this way without paying its mana cost. Put the rest on the bottom of your library in a random order.

Sky-Eel School

Flying
When Sky-Eel School enters the battlefield, draw a card, then discard a card.

Mystic Skyfish

Whenever you draw your second card each turn, Mystic Skyfish gains flying until end of turn.

Devouring Deep

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)

Fleet Swallower

Whenever Fleet Swallower attacks, target player mills half their library, rounded up.

Mountain

Island Fish Jasconius

Island Fish Jasconius doesn't untap during your untap step.
At the beginning of your upkeep, you may pay {U}{U}{U}. If you do, untap Island Fish Jasconius.
Island Fish Jasconius can't attack unless defending player controls an Island.
When you control no Islands, sacrifice Island Fish Jasconius.

Electric Eel

When Electric Eel enters the battlefield, it deals 1 damage to you.
{R}{R}: Electric Eel gets +2/+0 until end of turn and deals 1 damage to you.

Unclaimed Territory

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

Jace's Mindseeker

Flying
When Jace's Mindseeker enters the battlefield, target opponent mills five cards. You may cast an instant or sorcery spell from among them without paying its mana cost.

Arcane Signet

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

Kapsho Kitefins

Flying
Whenever Kapsho Kitefins or another creature enters the battlefield under your control, tap target creature an opponent controls.

Prismatic Vista

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

Homeward Path

{T}: Add {C}.
{T}: Each player gains control of all creatures they own.

Inevitable Betrayal

Suspend 3—{1}{U}{U} (Rather than cast this card from your hand, pay {1}{U}{U} and exile it with three time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)
Search target opponent's library for a creature card and put that card onto the battlefield under your control. Then that player shuffles.

Ancient Carp

Imoti, Celebrant of Bounty

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom of your library in a random order.)
Spells you cast with mana value 6 or greater have cascade.

Windrider Eel

Flying
Landfall — Whenever a land enters the battlefield under your control, Windrider Eel gets +2/+2 until end of turn.

Thawing Glaciers

Thawing Glaciers enters the battlefield tapped.
{1}, {T}: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle. Return Thawing Glaciers to its owner's hand at the beginning of the next cleanup step.

Plaza of Heroes

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a legendary spell.
{T}: Add one mana of any color among legendary permanents you control.
{3}, {T}, Exile Plaza of Heroes: Target legendary creature gains hexproof and indestructible until end of turn.

Moat Piranhas

Nesting Grounds

{T}: Add {C}.
{1}, {T}: Move a counter from target permanent you control onto another target permanent. Activate only as a sorcery.

Bounding Krasis

Flash (You may cast this spell any time you could cast an instant.)
When Bounding Krasis enters the battlefield, you may tap or untap target creature.

Breaching Hippocamp

Flash (You may cast this spell any time you could cast an instant.)
When Breaching Hippocamp enters the battlefield, untap another target creature you control.

Skitter Eel

{2}{U}: Adapt 2. (If this creature has no +1/+1 counters on it, put two +1/+1 counters on it.)

Abaddon the Despoiler

Trample
Mark of Chaos Ascendant — During your turn, spells you cast from your hand with mana value X or less have cascade, where X is the total amount of life your opponents have lost this turn.

Gurmag Angler

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)

Forbidden Orchard

{T}: Add one mana of any color.
Whenever you tap Forbidden Orchard for mana, target opponent creates a 1/1 colorless Spirit creature token.

Quagmire Lamprey

Whenever Quagmire Lamprey becomes blocked by a creature, put a -1/-1 counter on that creature.

Lost Vale

(Transforms from Dowsing Dagger.)
{T}: Add three mana of any one color.

Dowsing Dagger

When Dowsing Dagger enters the battlefield, target opponent creates two 0/2 green Plant creature tokens with defender.
Equipped creature gets +2/+1.
Whenever equipped creature deals combat damage to a player, you may transform Dowsing Dagger.
Equip {2}

Dowsing Dagger // Lost Vale

Secluded Courtyard

As Secluded Courtyard enters the battlefield, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type or activate an ability of a creature source of the chosen type.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Temur Ascendancy

Creatures you control have haste.
Whenever a creature with power 4 or greater enters the battlefield under your control, you may draw a card.

Skyreach Manta

Sunburst (This enters the battlefield with a +1/+1 counter on it for each color of mana spent to cast it.)
Flying

Bigger on the Inside

Enchant artifact or land
Enchanted permanent has "{T}: Target player adds two mana of any one color. The next spell they cast this turn has cascade." (When they cast their next spell, they exile cards from the top of their library until they exile a nonland card that costs less. They may cast it without paying its mana cost. They put the exiled cards on the bottom in a random order.)

Profane Tutor

Suspend 2—{1}{B} (Rather than cast this card from your hand, pay {1}{B} and exile it with two time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)
Search your library for a card, put that card into your hand, then shuffle.

Forest

Growth Spiral

Draw a card. You may put a land card from your hand onto the battlefield.

Command Tower

Ancient Ziggurat

{T}: Add one mana of any color. Spend this mana only to cast a creature spell.

Call Forth the Tempest

Cascade, cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom of your library in a random order. Then do it again.)
Call Forth the Tempest deals damage to each creature your opponents control equal to the total mana value of other spells you've cast this turn.

Cascading Cataracts

Indestructible
{T}: Add {C}.
{5}, {T}: Add five mana in any combination of colors.

Manta Ray

Manta Ray can't attack unless defending player controls an Island.
Manta Ray can't be blocked except by blue creatures.
When you control no Islands, sacrifice Manta Ray.

Reflecting Pool

{T}: Add one mana of any type that a land you control could produce.

Vampiric Tutor

Search your library for a card, then shuffle and put that card on top. You lose 2 life.

Apex Devastator

Cascade, cascade, cascade, cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom of your library in a random order. Multiple instances of cascade each trigger separately.)

Skyswimmer Koi

Flying
Whenever an artifact enters the battlefield under your control, you may draw a card. If you do, discard a card.

Elusive Krasis

Elusive Krasis can't be blocked.
Evolve (Whenever a creature enters the battlefield under your control, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Island

Fishliver Oil

Enchant creature (Target a creature as you cast this. This card enters the battlefield attached to that creature.)
Enchanted creature has islandwalk. (It can't be blocked as long as defending player controls an Island.)

School of Piranha

At the beginning of your upkeep, sacrifice School of Piranha unless you pay {1}{U}.

Farseek

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

Cavern of Souls

As Cavern of Souls enters the battlefield, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

Slipstream Eel

Slipstream Eel can't attack unless defending player controls an Island.
Cycling {1}{U} ({1}{U}, Discard this card: Draw a card.)

Yidris, Maelstrom Wielder

Trample
Whenever Yidris, Maelstrom Wielder deals combat damage to a player, as you cast spells from your hand this turn, they gain cascade. (When you cast the spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom of your library in a random order.)

Aboleth Spawn

Flash
Ward {2}
Probing Telepathy — Whenever a creature entering the battlefield under an opponent's control causes a triggered ability of that creature to trigger, you may copy that ability. You may choose new targets for the copy.