Sudden Spinnerets

Target creature gets +1/+3 until end of turn. Put a reach counter on it. Untap it.

Essence Scatter

Eternity Snare

Enchant creature
When Eternity Snare enters the battlefield, draw a card.
Enchanted creature doesn't untap during its controller's untap step.

Shipwreck Dowser

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When Shipwreck Dowser enters the battlefield, return target instant or sorcery card from your graveyard to your hand.

Phase Dolphin

Whenever Phase Dolphin attacks, another target attacking creature can't be blocked this turn.

Sharktocrab

{2}{G}{U}: Adapt 1. (If this creature has no +1/+1 counters on it, put a +1/+1 counter on it.)
Whenever one or more +1/+1 counters are put on Sharktocrab, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

Kenessos, Priest of Thassa

If you would scry a number of cards, scry that many cards plus one instead.
{3}{G/U}: Look at the top card of your library. If it's a Kraken, Leviathan, Octopus, or Serpent creature card, you may put it onto the battlefield. If you don't put the card onto the battlefield, you may put it on the bottom of your library.

Watertrap Weaver

When Watertrap Weaver enters the battlefield, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

Brinelin, the Moon Kraken

When Brinelin, the Moon Kraken enters the battlefield or whenever you cast a spell with mana value 6 or greater, you may return target nonland permanent to its owner's hand.
Partner (You can have two commanders if both have partner.)

Frostveil Ambush

Tap up to two target creatures. Those creatures don't untap during their controller's next untap step.
Cycling {1} ({1}, Discard this card: Draw a card.)

Anticipate

Look at the top three cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

Preordain

Scry 2, then draw a card. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Thwart the Enemy

Prevent all damage that would be dealt this turn by creatures your opponents control.

Trench Behemoth

Return a land you control to its owner's hand: Untap Trench Behemoth. It gains hexproof until end of turn.
Landfall — Whenever a land enters the battlefield under your control, target creature an opponent controls attacks during its controller's next combat phase if able.

Island

Wishful Merfolk

Defender
{1}{U}: Wishful Merfolk loses defender and becomes a Human until end of turn.

Crashing Tide

This spell has flash as long as you control a Merfolk.
Return target creature to its owner's hand.
Draw a card.

Leyline Invocation

Create a 0/0 green and blue Fractal creature token. Put X +1/+1 counters on it, where X is the number of lands you control.

Selkie Hedge-Mage

When Selkie Hedge-Mage enters the battlefield, if you control two or more Forests, you may gain 3 life.
When Selkie Hedge-Mage enters the battlefield, if you control two or more Islands, you may return target tapped creature to its owner's hand.

Aether Helix

Return target permanent to its owner's hand. Return target permanent card from your graveyard to your hand.

Thriving Isle

Thriving Isle enters the battlefield tapped.
As Thriving Isle enters the battlefield, choose a color other than blue.
{T}: Add {U} or one mana of the chosen color.

Capture Sphere

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
When Capture Sphere enters the battlefield, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Kiora, Sovereign of the Deep

Vigilance, ward {3}
Whenever you cast a Kraken, Leviathan, Octopus, or Serpent spell from your hand, look at the top X cards of your library, where X is that spell's mana value. You may cast a spell with mana value less than X from among them without paying its mana cost. Put the rest on the bottom of your library in a random order.

Wizard Class

(Gain the next level as a sorcery to add its ability.)
You have no maximum hand size.
{2}{U}: Level 2
When this Class becomes level 2, draw two cards.
{4}{U}: Level 3
Whenever you draw a card, put a +1/+1 counter on target creature you control.

Tromokratis

Tromokratis has hexproof unless it's attacking or blocking.
Tromokratis can't be blocked unless all creatures defending player controls block it. (If any creature that player controls doesn't block this creature, it can't be blocked.)

Cryptic Serpent

This spell costs {1} less to cast for each instant and sorcery card in your graveyard.

Zegana, Utopian Speaker

When Zegana, Utopian Speaker enters the battlefield, if you control another creature with a +1/+1 counter on it, draw a card.
{4}{G}{U}: Adapt 4. (If this creature has no +1/+1 counters on it, put four +1/+1 counters on it.)
Each creature you control with a +1/+1 counter on it has trample.

Hampering Snare

Creatures your opponents control get -2/-0 until end of turn.
Cycling {2} ({2}, Discard this card: Draw a card.)

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.

Explorer's Scope

Whenever equipped creature attacks, look at the top card of your library. If it's a land card, you may put it onto the battlefield tapped.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Fully Grown

Target creature gets +3/+3 until end of turn. Put a trample counter on it.

Tatyova, Steward of Tides

Land creatures you control have flying.
Whenever a land enters the battlefield under your control, if you control seven or more lands, up to one target land you control becomes a 3/3 Elemental creature with haste. It's still a land.

Forest

Mystic Subdual

Flash
Enchant creature
Enchanted creature gets -2/-0 and loses all abilities. (Mutating onto the creature won't give it new abilities. It can gain abilities in other ways.)

Saltwater Stalwart

Whenever Saltwater Stalwart deals damage to an opponent, target player draws a card.

River Sneak

River Sneak can't be blocked.
Whenever another Merfolk enters the battlefield under your control, River Sneak gets +1/+1 until end of turn.

Convolute

Counter target spell unless its controller pays {4}.

Curate

Surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
Draw a card.

Vineglimmer Snarl

As Vineglimmer Snarl enters the battlefield, you may reveal a Forest or Island card from your hand. If you don't, Vineglimmer Snarl enters the battlefield tapped.
{T}: Add {G} or {U}.

Field Trip

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

Take Flight

Enchant creature
Enchanted creature gets +1/+0 and has flying and "Whenever this creature attacks, draw a card."

Triton Shorestalker

Adventurous Impulse

Look at the top three cards of your library. You may reveal a creature or land card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Lay Claim

Enchant permanent
You control enchanted permanent.
Cycling {2} ({2}, Discard this card: Draw a card.)

Weakstone's Subjugation

Enchant artifact or creature
When Weakstone's Subjugation enters the battlefield, you may pay {3}. If you do, tap enchanted permanent.
Enchanted permanent doesn't untap during its controller's untap step.

Soul Read

Choose one —
• Counter target spell unless its controller pays {4}.
• Draw two cards.

Reservoir Kraken

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

Shipbreaker Kraken

{6}{U}{U}: Monstrosity 4. (If this creature isn't monstrous, put four +1/+1 counters on it and it becomes monstrous.)
When Shipbreaker Kraken becomes monstrous, tap up to four target creatures. Those creatures don't untap during their controllers' untap steps for as long as you control Shipbreaker Kraken.

Windrider Patrol

Flying
Whenever Windrider Patrol deals combat damage to a player, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

Tolarian Kraken

Whenever you draw a card, you may pay {1}. When you do, you may tap or untap target creature.

Thornwood Falls

Thornwood Falls enters the battlefield tapped.
When Thornwood Falls enters the battlefield, you gain 1 life.
{T}: Add {G} or {U}.

Harbinger of the Tides

You may cast Harbinger of the Tides as though it had flash if you pay {2} more to cast it. (You may cast it any time you could cast an instant.)
When Harbinger of the Tides enters the battlefield, you may return target tapped creature an opponent controls to its owner's hand.

Keep Safe

Counter target spell that targets a permanent you control.
Draw a card.

Hieroglyphic Illumination

Draw two cards.
Cycling {U} ({U}, Discard this card: Draw a card.)

Biblioplex Kraken

When Biblioplex Kraken enters the battlefield, scry 3. (Look at the top three cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)
Whenever Biblioplex Kraken attacks, you may return another creature you control to its owner's hand. If you do, Biblioplex Kraken can't be blocked this turn.

Growth Spiral

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

Kopala, Warden of Waves

Spells your opponents cast that target a Merfolk you control cost {2} more to cast.
Abilities your opponents activate that target a Merfolk you control cost {2} more to activate.

Simic Fluxmage

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.)
{1}{U}, {T}: Move a +1/+1 counter from Simic Fluxmage onto target creature.

Broken Wings

Destroy target artifact, enchantment, or creature with flying.

Tatyova, Benthic Druid

Landfall — Whenever a land enters the battlefield under your control, you gain 1 life and draw a card.

Arixmethes, Slumbering Isle

Arixmethes, Slumbering Isle enters the battlefield tapped with five slumber counters on it.
As long as Arixmethes has a slumber counter on it, it's a land. (It's not a creature.)
Whenever you cast a spell, you may remove a slumber counter from Arixmethes.
{T}: Add {G}{U}.

Greataxe

Equipped creature gets +4/+0.
Equip {5} ({5}: Attach to target creature you control. Equip only as a sorcery.)

Hedron Archive

{T}: Add {C}{C}.
{2}, {T}, Sacrifice Hedron Archive: Draw two cards.

Svyelun of Sea and Sky

Svyelun of Sea and Sky has indestructible as long as you control at least two other Merfolk.
Whenever Svyelun attacks, draw a card.
Other Merfolk you control have ward {1}. (Whenever another Merfolk you control becomes the target of a spell or ability an opponent controls, counter it unless that player pays {1}.)

Quandrix Campus

Quandrix Campus enters the battlefield tapped.
{T}: Add {G} or {U}.
{4}, {T}: Scry 1.

Spined Megalodon

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
Whenever Spined Megalodon attacks, scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

Merrow Reejerey

Other Merfolk creatures you control get +1/+1.
Whenever you cast a Merfolk spell, you may tap or untap target permanent.

Djinn of Wishes

Flying
Djinn of Wishes enters the battlefield with three wish counters on it.
{2}{U}{U}, Remove a wish counter from Djinn of Wishes: Reveal the top card of your library. You may play that card without paying its mana cost. If you don't, exile it.

Merfolk Mistbinder

Golden Ratio

Draw a card for each different power among creatures you control.

Merfolk Skydiver

Flying
When Merfolk Skydiver enters the battlefield, put a +1/+1 counter on target creature you control.
{3}{G}{U}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Grafted Growth

Enchant land
When Grafted Growth enters the battlefield, put a +1/+1 counter on target creature or Vehicle you control.
Enchanted land has "{T}: Add two mana of any one color."

Quandrix Pledgemage

Magecraft — Whenever you cast or copy an instant or sorcery spell, put a +1/+1 counter on Quandrix Pledgemage.

Tishana, Voice of Thunder

Tishana, Voice of Thunder's power and toughness are each equal to the number of cards in your hand.
You have no maximum hand size.
When Tishana enters the battlefield, draw a card for each creature you control.

Weather the Storm

You gain 3 life.
Storm (When you cast this spell, copy it for each spell cast before it this turn.)