Quagmire Lamprey

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

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Frost Fair Lure Fish

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

Merieke Ri Berit

Merieke Ri Berit doesn't untap during your untap step.
{T}: Gain control of target creature for as long as you control Merieke Ri Berit. When Merieke Ri Berit leaves the battlefield or becomes untapped, destroy that creature. It can't be regenerated.

Expendable Lackey

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

Into the Fray

Target creature attacks this turn if able.
Splice onto Arcane {R} (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.)

Boiling Blood

Target creature attacks this turn if able.
Draw a card.

Forest

Sazacap's Brew

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.)
As an additional cost to cast this spell, discard a card.
Target player draws two cards. If the gift was promised, target creature you control gets +2/+0 until end of turn.

Herald's Horn

As Herald's Horn enters, choose a creature type.
Creature spells you cast of the chosen type cost {1} less to cast.
At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.

Cinder Glade

({T}: Add {R} or {G}.)
Cinder Glade enters tapped unless you control two or more basic lands.

Exotic Pets

Create two 1/1 blue Fish creature tokens with "This creature 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.

Kapsho Kitefins

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

Command Tower

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

Magda, the Hoardmaster

Whenever you commit a crime, create a tapped Treasure token. This ability triggers only once each turn. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime.)
Sacrifice three Treasures: Create a 4/4 red Scorpion Dragon creature token with flying and haste. Activate only as a sorcery.

Island

Coral Eel

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.

Roiling Regrowth

Sacrifice a land. Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Exotic Orchard

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

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.)

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 Starforged Sword enters, if the gift was promised, attach Starforged Sword to target creature you control.
Equipped creature gets +3/+3 and loses flying.
Equip {3}

Training Center

Training Center enters tapped unless you have two or more opponents.
{T}: Add {U} or {R}.

Frontier Bivouac

Frontier Bivouac enters tapped.
{T}: Add {G}, {U}, or {R}.

Breaching Hippocamp

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

Chemister's Trick

Target creature you don't control gets -2/-0 until end of turn and attacks this turn if able.
Overload {3}{U}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Aggravate

Aggravate deals 1 damage to each creature target player controls. Each creature dealt damage this way attacks this turn if able.

Steam Vents

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

Knightfisher

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

Luminescent Rain

Choose a creature type. You gain 2 life for each permanent you control of that type.

Blufferfish

{3}{U}: An opponent tells you a statement about themselves and secretly notes whether it's true or false. You guess which it is. If you guessed correctly, Blufferfish gets +2/+0 and can't be blocked this turn.

Yasova Dragonclaw

Trample
At the beginning of combat on your turn, you may pay {1}{U/R}{U/R}. If you do, gain control of target creature an opponent controls with power less than Yasova Dragonclaw's power until end of turn, untap that creature, and it gains haste until end of turn.

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.

Heckling Fiends

{2}{R}: Target creature attacks this turn if able.

Bullwhip

{2}, {T}: Bullwhip deals 1 damage to target creature. That creature attacks this turn if able.

Hardbristle Bandit

{T}: Add one mana of any color.
Whenever you commit a crime, untap Hardbristle Bandit. This ability triggers only once each turn. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime.)

Courtly Provocateur

{T}: Target creature attacks this turn if able.
{T}: Target creature blocks this turn if able.

Shipwreck Moray

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

Strength in Numbers

Until end of turn, target creature gains trample and gets +X/+X, where X is the number of attacking creatures.

Wooded Foothills

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

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 creature to the battlefield under its owner's control with a +1/+1 counter on it at the beginning of the next end step.

Ketria Triome

({T}: Add {G}, {U}, or {R}.)
Ketria Triome enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

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.)

Devouring Deep

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

Gurmag Angler

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

Hunt Down

Target creature blocks target creature this turn if able.

Rootbound Crag

Rootbound Crag enters tapped unless you control a Mountain or a Forest.
{T}: Add {R} or {G}.

Imps' Taunt

Buyback {3} (You may pay an additional {3} as you cast this spell. If you do, put this card into your hand as it resolves.)
Target creature attacks this turn if able.

Galadhrim Ambush

Create X 1/1 green Elf Warrior creature tokens, where X is the number of attacking creatures.
Prevent all combat damage that would be dealt this turn by non-Elf creatures.

Mystic Skyfish

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

Norritt

{T}: Untap target blue creature.
{T}: Choose target non-Wall creature the active player has controlled continuously since the beginning of the turn. That creature attacks this turn if able. Destroy it at the beginning of the next end step if it didn't attack this turn. Activate only before attackers are declared.

Progenitor's Icon

As Progenitor's Icon enters, choose a creature type.
{T}: Add one mana of any color.
{T}: The next spell of the chosen type you cast this turn can be cast as though it had flash.

Kiora, Master of the Depths

+1: Untap up to one target creature and up to one target land.
−2: 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.
−8: You get an emblem with "Whenever a creature you control enters, you may have it fight target creature." Then create three 8/8 blue Octopus creature tokens.

Tidal Barracuda

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

Rage Nimbus

Defender, flying
{1}{R}: Target creature attacks this turn if able.

Sleep with the Fishes

Enchant creature
When Sleep with the Fishes enters, 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.

Kodama's Reach

Reef Worm

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

Dandân

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

Stomping Ground

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

Academy Ruins

{T}: Add {C}.
{1}{U}, {T}: Put target artifact card from your graveyard on top of your library.

Wormfang Behemoth

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

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.

Mountain

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 Grizzled Angler.

Grizzled Angler // Grisly Anglerfish

Coral Atoll

Coral Atoll enters tapped.
When Coral Atoll enters, sacrifice it unless you return an untapped Island you control to its owner's hand.
{T}: Add {C}{U}.

Cavern of Souls

As Cavern of Souls enters, 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.

Academic Dispute

Target creature blocks this turn if able. You may have it gain reach until end of turn.
Learn. (You may reveal a Lesson card you own from outside the game and put it into your hand, or discard a card to draw a card.)

Angler Drake

Flying
When Angler Drake enters, you may return target creature to its owner's hand.

Fumiko the Lowblood

Fumiko the Lowblood has bushido X, where X is the number of attacking creatures. (Whenever this creature blocks or becomes blocked, it gets +X/+X until end of turn.)
Creatures your opponents control attack each combat if able.

Spiny Starfish

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

Spire Garden

Spire Garden enters tapped unless you have two or more opponents.
{T}: Add {R} or {G}.

Electric Eel

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

Hinterland Harbor

Hinterland Harbor enters tapped unless you control a Forest or an Island.
{T}: Add {G} or {U}.

Sulfur Falls

Sulfur Falls enters tapped unless you control an Island or a Mountain.
{T}: Add {U} or {R}.

Stonybrook Angler

{1}{U}, {T}: You may tap or untap target creature.

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.

Cloud Manta

Beza, the Bounding Spring

When Beza, the Bounding Spring 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.

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.

Rubinia Soulsinger

You may choose not to untap Rubinia Soulsinger during your untap step.
{T}: Gain control of target creature for as long as you control Rubinia and Rubinia remains tapped.

Nettling Curse

Enchant creature
Whenever enchanted creature attacks or blocks, its controller loses 3 life.
{1}{R}: Enchanted creature attacks this turn if able.

Fleet Swallower

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

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 artifact: Draw a card.")
Whenever you draw your second card each turn, put two +1/+1 counters on Morska, Undersea Sleuth.

Dispel

Sol Ring

Angler Turtle

Hexproof
Creatures your opponents control attack each combat if able.

Goblin Diplomats

{T}: Each creature attacks this turn if able.

Skitter Eel

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

Ancient Carp

Incite

Target creature becomes red until end of turn and attacks this turn if able.

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.

School of Piranha

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

Arcum's Whistle

{3}, {T}: Choose target non-Wall creature the active player has controlled continuously since the beginning of the turn. That player may pay {X}, where X is that mana value. If they don't pay, the creature attacks this turn if able, and at the beginning of the next end step, destroy it if it didn't attack this turn. Activate only before attackers are declared.

Seafloor Debris

Seafloor Debris enters tapped.
{T}: Add {U}.
{T}, Sacrifice Seafloor Debris: Add one mana of any color.

Molten Tributary

({T}: Add {U} or {R}.)
Molten Tributary enters tapped.

Sky-Eel School

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

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.

Wonder

Flying
As long as Wonder is in your graveyard and you control an Island, creatures you control have flying.

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.

Jace's Mindseeker

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

Skyreach Manta

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

Culling Mark

Target creature blocks this turn if able.

Wormfang Manta

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