School of Piranha

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

Breeding Pool

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

Manta Ray

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

Coral Eel

Sky-Eel School

Flying
When this creature enters, draw a card, then discard a card.

Bubble Smuggler

Disguise {5}{U} (You may cast this card face down for {3} as a 2/2 creature with ward {2}. Turn it face up any time for its disguise cost.)
As this creature is turned face up, put four +1/+1 counters on it.

Reef Worm

When this creature dies, create a 3/3 blue Fish creature token with "When this token dies, create a 6/6 blue Whale creature token with 'When this token dies, create a 9/9 blue Kraken creature token.'"

Wavebreak Hippocamp

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

Shipwreck Moray

When this creature enters, you get {E}{E}{E}{E} (four energy counters).
Pay {E}: This creature gets +2/-2 until end of turn.

Deepglow Skate

When this creature enters, double the number of each kind of counter on any number of target permanents.

Island Fish Jasconius

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

Eluge, the Shoreless Sea

Eluge's power and toughness are each equal to the number of Islands you control.
Whenever Eluge enters or attacks, put a flood counter on target land. It's an Island in addition to its other types for as long as it has a flood counter on it.
The first instant or sorcery spell you cast each turn costs {U} (or {1}) less to cast for each land you control with a flood counter on it.

Coat of Arms

Each creature gets +1/+1 for each other creature on the battlefield that shares at least one creature type with it. (For example, if two Goblin Warriors and a Goblin Shaman are on the battlefield, each gets +2/+2.)

Knightfisher

Flying
Whenever another nontoken Bird you control enters, create a 1/1 blue Fish creature token.

Forest

Tranquil Landscape

{T}: Add {C}.
{T}, Sacrifice this land: Search your library for a basic Forest, Plains, or Island card, put it onto the battlefield tapped, then shuffle.
Cycling {G}{W}{U} ({G}{W}{U}, Discard this card: Draw a card.)

Island

Skyreach Manta

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

Parting Gust

Gift a tapped Fish (You may promise an opponent a gift as you cast this spell. If you do, they create a tapped 1/1 blue Fish creature token before its other effects.)
Exile target nontoken creature. If the gift wasn't promised, return that card to the battlefield under its owner's control with a +1/+1 counter on it at the beginning of the next end step.

Icon of Ancestry

As this artifact enters, 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.

Spara's Headquarters

({T}: Add {G}, {W}, or {U}.)
This land enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Distant Melody

Choose a creature type. Draw a card for each permanent you control of that type.

Scrounging Skyray

Flying
Whenever you discard one or more cards, put that many +1/+1 counters on this creature.
Cycling {2} ({2}, Discard this card: Draw a card.)

Evolving Wilds

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

Adrix and Nev, Twincasters

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
If one or more tokens would be created under your control, twice that many of those tokens are created instead.

Esix, Fractal Bloom

Flying
The first time you would create one or more tokens during each of your turns, you may instead choose a creature other than Esix and create that many tokens that are copies of that creature.

Tidal Barracuda

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

Brokers Hideout

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

Morska, Undersea Sleuth

You have no maximum hand size.
At the beginning of your upkeep, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")
Whenever you draw your second card each turn, put two +1/+1 counters on Morska.

Aboleth Spawn

Flash
Ward {2}
Probing Telepathy — Whenever a creature entering 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.

Windrider Eel

Flying
Landfall — Whenever a land you control enters, this creature gets +2/+2 until end of turn.

Skitter Eel

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

Mystic Skyfish

Whenever you draw your second card each turn, this creature gains flying until end of turn.

Fleet Swallower

Whenever this creature attacks, target player mills half their library, rounded up.

Cloud Manta

Reliquary Tower

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

Skyswimmer Koi

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

Hallowed Fountain

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

Devouring Deep

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

Ichthyomorphosis

Enchant creature
Enchanted creature loses all abilities and is a blue Fish with base power and toughness 0/1.

Reservoir Kraken

Trample, ward {2}
At the beginning of each combat, if this creature is untapped, any opponent may tap an untapped creature they control. If they do, tap this creature and create a 1/1 blue Fish creature token with "This token can't be blocked."

Instruments of War

Flash
As this artifact enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.

Moat Piranhas

Ancient Carp

Fisher's Talent

(Gain the next level as a sorcery to add its ability.)
At the beginning of your upkeep, look at the top card of your library. You may reveal it if it's a land card. Create a 1/1 blue Fish creature token if you revealed it this way. Then draw a card.
{G}{U}: Level 2
If you would create a Fish token, create a 3/3 blue Shark creature token instead.
{2}{G}{U}: Level 3
If you would create a Shark token, create an 8/8 blue Octopus creature token instead.

Spiny Starfish

{U}: Regenerate this creature.
At the beginning of each end step, if this creature regenerated this turn, create a 0/1 blue Starfish creature token for each time it regenerated this turn.

Wormfang Manta

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

Command Tower

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

Academy Manufactor

If you would create a Clue, Food, or Treasure token, instead create one of each.

Vanquisher's Banner

As this artifact enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
Whenever you cast a creature spell of the chosen type, draw a card.

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.

Wormfang Behemoth

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

Into the Flood Maw

Gift a tapped Fish (You may promise an opponent a gift as you cast this spell. If you do, they create a tapped 1/1 blue Fish creature token before its other effects.)
Return target creature an opponent controls to its owner's hand. If the gift was promised, instead return target nonland permanent an opponent controls to its owner's hand.

Slipstream Eel

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

Flooded Strand

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

Beza, the Bounding Spring

When Beza enters, create a Treasure token if an opponent controls more lands than you. You gain 4 life if an opponent has more life than you. Create two 1/1 blue Fish creature tokens if an opponent controls more creatures than you. Draw a card if an opponent has more cards in hand than you.

Sleep with the Fishes

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

Exotic Orchard

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

Longstalk Brawl

Gift a tapped Fish (You may promise an opponent a gift as you cast this spell. If you do, they create a tapped 1/1 blue Fish creature token before its other effects.)
Choose target creature you control and target creature you don't control. Put a +1/+1 counter on the creature you control if the gift was promised. Then those creatures fight each other.

Kapsho Kitefins

Flying
Whenever this creature or another creature you control enters, tap target creature an opponent controls.

Exotic Pets

Create two 1/1 blue Fish creature tokens with "This token can't be blocked." Then for each kind of counter among creatures you control, put a counter of that kind on either of those tokens.

Reflections of Littjara

As this enchantment enters, choose a creature type.
Whenever you cast a spell of the chosen type, copy that spell. (A copy of a permanent spell becomes a token.)

Stinging Lionfish

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

Bounding Krasis

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

Breaching Hippocamp

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

Seaside Citadel

This land enters tapped.
{T}: Add {G}, {W}, or {U}.

Surge Mare

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

Canopy Vista

({T}: Add {G} or {W}.)
This land enters tapped unless you control two or more basic lands.

Plains

Fishing Pole

Equipped creature has "{1}, {T}, Tap Fishing Pole: Put a bait counter on Fishing Pole."
Whenever equipped creature becomes untapped, remove a bait counter from this Equipment. If you do, create a 1/1 blue Fish creature token.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Jace's Mindseeker

Flying
When this creature enters, target opponent mills five cards. You may cast an instant or sorcery spell from among them without paying its mana cost.

Prairie Stream

({T}: Add {W} or {U}.)
This land enters tapped unless you control two or more basic lands.

Selesnya Sanctuary

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {G}{W}.

Path of Ancestry

This land enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Simic Growth Chamber

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {G}{U}.

Dandân

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

Expendable Lackey

{1}{U}, Exile this card from your graveyard: Create a 1/1 blue Fish creature token with "This token can't be blocked." Activate only as a sorcery.

Elusive Krasis

This creature can't be blocked.
Evolve (Whenever a creature you control enters, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)

Vivid Flying Fish

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

Temple Garden

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

Starforged Sword

Gift a tapped Fish (You may promise an opponent a gift as you cast this spell. If you do, when it enters, they create a tapped 1/1 blue Fish creature token.)
When this Equipment enters, if the gift was promised, attach this Equipment to target creature you control.
Equipped creature gets +3/+3 and loses flying.
Equip {3}

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.

Azorius Chancery

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {W}{U}.

Grisly Anglerfish

{6}: Creatures your opponents control attack this turn if able.

Grizzled Angler

{T}: Mill two cards. Then if there is a colorless creature card in your graveyard, transform this creature. (To mill two cards, put the top two cards of your library into your graveyard.)

Grizzled Angler // Grisly Anglerfish

Mind Spiral

Gift a tapped Fish (You may promise an opponent a gift as you cast this spell. If you do, they create a tapped 1/1 blue Fish creature token before its other effects.)
Target player draws three cards. If the gift was promised, tap target creature an opponent controls and put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)

Piranha Fly

Fountainport

{T}: Add {C}.
{2}, {T}, Sacrifice a token: Draw a card.
{3}, {T}, Pay 1 life: Create a 1/1 blue Fish creature token.
{4}, {T}: Create a Treasure token.

Door of Destinies

As this artifact enters, choose a creature type.
Whenever you cast a spell of the chosen type, put a charge counter on this artifact.
Creatures you control of the chosen type get +1/+1 for each charge counter on this artifact.