Command Tower

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

Seafloor Oracle

Whenever a Merfolk you control deals combat damage to a player, draw a card.

Alley Strangler

Teferi's Protege

{1}{U}, {T}: Draw a card, then discard a card.

Termination Facilitator

{T}: Put a bounty counter on target creature or planeswalker. Activate only as a sorcery.
Whenever a creature or planeswalker an opponent controls with a bounty counter on it is dealt damage, destroy it.

Hunter's Edge

Put a +1/+1 counter on target creature you control. Then that creature deals damage equal to its power to target creature you don't control.

Thriving Moor

Thriving Moor enters the battlefield tapped.
As Thriving Moor enters the battlefield, choose a color other than black.
{T}: Add {B} or one mana of the chosen color.

Triton Shorestalker

Faerie Vandal

Flash
Flying
Whenever you draw your second card each turn, put a +1/+1 counter on Faerie Vandal.

Spectral Sailor

Flash (You may cast this spell any time you could cast an instant.)
Flying
{3}{U}: Draw a card.

Jace, Arcane Strategist

Whenever you draw your second card each turn, put a +1/+1 counter on target creature you control.
+1: Draw a card.
−7: Creatures you control can't be blocked this turn.

Ever-Watching Threshold

Whenever an opponent attacks, if they attacked you and/or a planeswalker you control, draw a card.

Swarm Shambler

Swarm Shambler enters the battlefield with a +1/+1 counter on it.
Whenever a creature you control with a +1/+1 counter on it becomes the target of a spell an opponent controls, create a 1/1 green Insect creature token.
{1}, {T}: Put a +1/+1 counter on Swarm Shambler.

Hedron Archive

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

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.

Vorosh, the Hunter

Flying
Whenever Vorosh, the Hunter deals combat damage to a player, you may pay {2}{G}. If you do, put six +1/+1 counters on Vorosh.

Vampire Envoy

Flying
Whenever Vampire Envoy becomes tapped, you gain 1 life.

Moment of Craving

Target creature gets -2/-2 until end of turn. You gain 2 life.

Winged Words

This spell costs {1} less to cast if you control a creature with flying.
Draw two cards.

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.

Cemetery Recruitment

Return target creature card from your graveyard to your hand. If it's a Zombie card, draw a card.

Windreader Sphinx

Flying
Whenever a creature with flying attacks, you may draw a card.

Nested Ghoul

Whenever a source deals damage to Nested Ghoul, create a 2/2 black Phyrexian Zombie creature token.

Arcane Signet

Inspired Sphinx

Flying
When Inspired Sphinx enters the battlefield, draw cards equal to the number of opponents you have.
{3}{U}: Create a 1/1 colorless Thopter artifact creature token with flying.

Oathsworn Vampire

Oathsworn Vampire enters the battlefield tapped.
You may cast Oathsworn Vampire from your graveyard if you gained life this turn.

Aquatic Incursion

When Aquatic Incursion enters the battlefield, create two 1/1 blue Merfolk creature tokens with hexproof. (They can't be the targets of spells or abilities your opponents control.)
{3}{U}: Target Merfolk can't be blocked this turn.

Marauding Blight-Priest

Whenever you gain life, each opponent loses 1 life.

Bloodtracker

Flying
{B}, Pay 2 life: Put a +1/+1 counter on Bloodtracker.
When Bloodtracker leaves the battlefield, draw a card for each +1/+1 counter on it.

Creeping Bloodsucker

At the beginning of your upkeep, Creeping Bloodsucker deals 1 damage to each opponent. You gain life equal to the damage dealt this way.

Caustic Caterpillar

{1}{G}, Sacrifice Caustic Caterpillar: Destroy target artifact or enchantment.

Favorable Winds

Creatures you control with flying get +1/+1.

Sky Diamond

Sky Diamond enters the battlefield tapped.
{T}: Add {U}.

Feast on the Fallen

At the beginning of each upkeep, if an opponent lost life last turn, put a +1/+1 counter on target creature you control.

Bad River

Bad River enters the battlefield tapped.
{T}, Sacrifice Bad River: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Nantuko Cultivator

When Nantuko Cultivator enters the battlefield, you may discard any number of land cards. Put that many +1/+1 counters on Nantuko Cultivator and draw that many cards.

Mire Blight

Enchant creature
When enchanted creature is dealt damage, destroy it.

Diluvian Primordial

Flying
When Diluvian Primordial enters the battlefield, for each opponent, you may cast up to one target instant or sorcery card from that player's graveyard without paying its mana cost. If a spell cast this way would be put into a graveyard, exile it instead.

Bident of Thassa

Whenever a creature you control deals combat damage to a player, you may draw a card.
{1}{U}, {T}: Creatures your opponents control attack this turn if able.

Shaper Apprentice

Shaper Apprentice has flying as long as you control another Merfolk.

Thought Vessel

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

Plague Spitter

At the beginning of your upkeep, Plague Spitter deals 1 damage to each creature and each player.
When Plague Spitter dies, it deals 1 damage to each creature and each player.

Sol Ring

Feast of Blood

Cast this spell only if you control two or more Vampires.
Destroy target creature. You gain 4 life.

Forest

Ashcoat of the Shadow Swarm

Whenever Ashcoat of the Shadow Swarm attacks or blocks, other Rats you control get +X/+X until end of turn, where X is the number of Rats you control.
At the beginning of your end step, you may mill four cards. If you do, return up to two Rat creature cards from your graveyard to your hand. (To mill a card, put the top card of your library into your graveyard.)

Giant Ladybug

Reach
When Giant Ladybug enters the battlefield, you may search your library for a basic land card, reveal it, then shuffle and put that card on top.

Crow of Dark Tidings

Flying
When Crow of Dark Tidings enters the battlefield or dies, mill two cards. (Put the top two cards of your library into your graveyard.)

Counterspell

Island

Bloodthirsty Aerialist

Flying
Whenever you gain life, put a +1/+1 counter on Bloodthirsty Aerialist.

Crawling Sensation

At the beginning of your upkeep, you may mill two cards.
Whenever one or more land cards are put into your graveyard from anywhere for the first time each turn, create a 1/1 green Insect creature token.

Necromancer's Stockpile

{1}{B}, Discard a creature card: Draw a card. If the discarded card was a Zombie card, create a tapped 2/2 black Zombie creature token.

Serum Visions

Certain Death

Destroy target creature. Its controller loses 2 life and you gain 2 life.

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.

Ill-Gotten Inheritance

At the beginning of your upkeep, Ill-Gotten Inheritance deals 1 damage to each opponent and you gain 1 life.
{5}{B}, Sacrifice Ill-Gotten Inheritance: It deals 4 damage to target opponent and you gain 4 life.

Aetherize

Return all attacking creatures to their owner's hand.

Drag Under

Return target creature to its owner's hand.
Draw a card.

Merrow Reejerey

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

Memorial to Genius

Memorial to Genius enters the battlefield tapped.
{T}: Add {U}.
{4}{U}, {T}, Sacrifice Memorial to Genius: Draw two cards.

Storm Sculptor

Storm Sculptor can't be blocked.
When Storm Sculptor enters the battlefield, return a creature you control to its owner's hand.

Moldgraf Millipede

When Moldgraf Millipede enters the battlefield, mill three cards, then put a +1/+1 counter on Moldgraf Millipede for each creature card in your graveyard. (To mill a card, put the top card of your library into your graveyard.)

One With the Wind

Enchant creature
Enchanted creature gets +2/+2 and has flying.

Nessian Hornbeetle

At the beginning of combat on your turn, if you control another creature with power 4 or greater, put a +1/+1 counter on Nessian Hornbeetle.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Merfolk Pupil

When Merfolk Pupil enters the battlefield, draw a card, then discard a card.
{1}{U}, Exile Merfolk Pupil from your graveyard: Draw a card, then discard a card.

Deadly Plot

Choose one —
• Destroy target creature or planeswalker.
• Return target Zombie creature card from your graveyard to the battlefield tapped.

Negate

Talon of Pain

Whenever a source you control other than Talon of Pain deals damage to an opponent, put a charge counter on Talon of Pain.
{X}, {T}, Remove X charge counters from Talon of Pain: It deals X damage to any target.

Epicure of Blood

Falkenrath Noble

Flying
Whenever Falkenrath Noble or another creature dies, target player loses 1 life and you gain 1 life.

Crashing Tide

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

Swamp

Eyekite

Flying
Eyekite gets +2/+0 as long as you've drawn two or more cards this turn.

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.

Ironshell Beetle

When Ironshell Beetle enters the battlefield, put a +1/+1 counter on target creature.

Duskshell Crawler

When Duskshell Crawler enters the battlefield, put a +1/+1 counter on target creature.
Each creature you control with a +1/+1 counter on it has trample.

Pilgrim's Eye

Flying
When Pilgrim's Eye enters the battlefield, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Infernal Idol

{T}: Add {B}.
{1}{B}{B}, {T}, Sacrifice Infernal Idol: You draw two cards and you lose 2 life.

Soul Read

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

Thriving Grove

Thriving Grove enters the battlefield tapped.
As Thriving Grove enters the battlefield, choose a color other than green.
{T}: Add {G} or one mana of the chosen color.