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

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.

You draw a card at the beginning of the next turn's upkeep.

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

{1}{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 Benthic Biomancer, draw a card, then discard a card.

Whenever a creature you control with a +1/+1 counter on it deals combat damage to a player, you may draw a card.

Whenever Cleric of Chill Depths blocks a creature, that creature doesn't untap during its controller's next untap step.

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

Whenever Cold-Eyed Selkie deals combat damage to a player, you may draw that many cards.

{1}{G}, {T}: This turn, each creature you control enters the battlefield with an additional +1/+1 counter on it.

{1}{U}, {T}: Move a +1/+1 counter from target creature you control onto another target creature you control.

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

Level up {1} ({1}: Put a level counter on this. Level up only as a sorcery.)

LEVEL 2-3

3/3

Flying

LEVEL 4+

4/4

Flying

Other Merfolk creatures you control get +1/+1.

Blue creatures you control can't be blocked.

Whenever another Merfolk enters the battlefield under your control, put a +1/+1 counter on target Merfolk you control.

Whenever one or more nontoken Merfolk you control become tapped, create a 1/1 blue Merfolk creature token with hexproof.

Whenever you cast a Merfolk spell, create a 1/1 blue Merfolk creature token with hexproof. (A creature with hexproof can't be the target of spells or abilities your opponents control.)

You may look at the top card of your library any time.

You may cast Merfolk spells from the top of your library.

Whenever you cast a Merfolk spell, you may pay {1}. If you do, create a 1/1 blue Merfolk creature token.

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

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

When Forerunner of the Heralds enters the battlefield, you may search your library for a Merfolk card, reveal it, then shuffle and put that card on top.

Whenever another Merfolk enters the battlefield under your control, put a +1/+1 counter on Forerunner of the Heralds.

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

Gray Harbor Merfolk can't be blocked.

Gray Harbor Merfolk gets +2/+0 as long as you control a commander that's a creature or planeswalker.

At the beginning of combat on your turn, each Merfolk creature you control explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on the exploring creature, then put the card back or put it into your graveyard.)

Whenever Hakbal of the Surging Soul attacks, you may put a land card from your hand onto the battlefield. If you don't, draw a card.

If one or more +1/+1 counters would be put on a creature you control, that many plus one +1/+1 counters are put on it instead.

Creatures you control with +1/+1 counters on them can't be blocked.

As Herald's Horn enters the battlefield, 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.

Hinterland Harbor enters the battlefield tapped unless you control a Forest or an Island.

{T}: Add {G} or {U}.

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

{T}: Untap another target permanent.

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.

Tap another untapped Merfolk you control: Kumena, Tyrant of Orazca can't be blocked this turn.

Tap three untapped Merfolk you control: Draw a card.

Tap five untapped Merfolk you control: Put a +1/+1 counter on each Merfolk you control.

Whenever Library Larcenist attacks, draw a card.

Whenever a spell or ability you control counters a spell, you may create a 1/1 blue Merfolk creature token.

Tap seven untapped Merfolk you control: Counter target spell.

Manor Gate enters the battlefield tapped.

As Manor Gate enters the battlefield, choose a color other than green.

{T}: Add {G} or one mana of the chosen color.

Other Merfolk creatures you control get +1/+1 and have islandwalk. (They can't be blocked as long as defending player controls an Island.)

Other Merfolk you control get +1/+1.

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.

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.)

Other Merfolk creatures you control get +1/+1.

{T}: Target Merfolk creature can't be blocked this turn.

When Merfolk Traders enters the battlefield, draw a card, then discard a card.

Flash

When Merfolk Trickster enters the battlefield, tap target creature an opponent controls. It loses all abilities until end of turn.

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

When Merrow Harbinger enters the battlefield, you may search your library for a Merfolk card, reveal it, then shuffle and put that card on top.

Other Merfolk creatures you control get +1/+1.

Whenever you cast a Merfolk spell, you may tap or untap target permanent.

Flying

Other Merfolk you control get +1/+0 and have flying.

Encore {5}{U}{U} ({5}{U}{U}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Mist-Cloaked Herald can't be blocked.

Sacrifice Mistcaller: Until end of turn, if a nontoken creature would enter the battlefield and it wasn't cast, exile it instead.

Permanents you control with counters on them gain hexproof and indestructible until end of turn. Prevent all damage that would be dealt to those permanents this turn. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Copy target instant or sorcery spell, then return it to its owner's hand. You may choose new targets for the copy.

Destroy target artifact or enchantment.

Destroy target artifact or enchantment. Its controller gains 4 life.

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

Whenever a creature you control explores a land card, you may put a land card from your hand onto the battlefield tapped.

Whenever a creature you control explores a nonland card, put a +1/+1 counter on Nicanzil, Current Conductor.

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

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

Destroy target creature. It can't be regenerated. That creature's controller creates a 3/3 green Frog Lizard creature token.

Exile target creature. Its controller manifests the top card of their library. (That player puts the top card of their library onto the battlefield face down as a 2/2 creature. If it's a creature card, it can be turned face up any time for its mana cost.)

Put X +1/+1 counters on target creature you control. Then counter up to one target spell unless its controller pays mana equal to the greatest power among creatures you control.

({T}: Add {G} or {U}.)

Rimewood Falls enters the battlefield tapped.

River Sneak can't be blocked.

Whenever another Merfolk enters the battlefield under your control, River Sneak gets +1/+1 until end of turn.

Sea Gate enters the battlefield tapped.

As Sea Gate enters the battlefield, choose a color other than blue.

{T}: Add {U} or one mana of the chosen color.

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

{3}, {T}: Search your library for a Merfolk permanent card, put it onto the battlefield, then shuffle.

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.

{1}, {T}: Add {G}{U}.

Flash

When Singer of Swift Rivers enters the battlefield, put a shield counter on another target creature you control. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)

You may cast Merfolk spells as though they had flash.

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

Merfolk spells and Wizard spells you cast cost {1} less to cast.

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}.)

Flash

When Swift Warden enters the battlefield, target Merfolk you control gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

{T}: Add {C}.

{T}: Add {G} or {U}. Talisman of Curiosity deals 1 damage to you.

({T}: Add {G} or {U}.)

Tangled Islet enters the battlefield tapped.

Tanglepool Bridge enters the battlefield tapped.

Indestructible

{T}: Add {G} or {U}.

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

When Tempest Caller enters the battlefield, tap all creatures target opponent controls.

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

Search your library for a Forest card, put it onto the battlefield, then shuffle.

When Topography Tracker enters the battlefield, create a Map token. (It's an artifact with "{1}, {T}, Sacrifice this artifact: Target creature you control explores. Activate only as a sorcery.")

If a creature you control would explore, instead it explores, then it explores again.

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)

Whenever a creature you control with a +1/+1 counter on it dies, draw a card.

Triton Shorestalker can't be blocked.

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.

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}.

Flash

Other Merfolk you control get +1/+1.

Sacrifice a Merfolk: Counter target noncreature spell unless its controller pays {1}.

Whenever a permanent you control becomes untapped, Wake Thrasher gets +1/+1 until end of turn.

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