Silvergill Peddler

Whenever this creature becomes tapped, draw a card, then discard a card.

Steam Vents

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

Silvergill Mentor

As an additional cost to cast this spell, behold a Merfolk or pay {2}. (To behold a Merfolk, choose a Merfolk you control or reveal a Merfolk from your hand.)
When this creature enters, create a 1/1 white and blue Merfolk creature token.

Flaring Cinder

When this creature enters and whenever you cast a spell with mana value 4 or greater, you may discard a card. If you do, draw a card.

Wanderbrine Preacher

Whenever this creature becomes tapped, you gain 2 life.

Merrow Skyswimmer

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Flying, vigilance
When this creature enters, create a 1/1 white and blue Merfolk creature token.

Meanders Guide

Whenever this creature attacks, you may tap another untapped Merfolk you control. When you do, return target creature card with mana value 3 or less from your graveyard to the battlefield.

Champions of the Shoal

As an additional cost to cast this spell, behold a Merfolk and exile it. (Exile a Merfolk you control or a Merfolk card from your hand.)
Whenever this creature enters or becomes tapped, tap up to one target creature and put a stun counter on it.
When this creature leaves the battlefield, return the exiled card to its owner's hand.

Hallowed Fountain

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

Curious Colossus

When this creature enters, each creature target opponent controls loses all abilities, becomes a Coward in addition to its other types, and has base power and toughness 1/1.

Eclipsed Flamekin

When this creature enters, look at the top four cards of your library. You may reveal an Elemental, Island, or Mountain card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Plains

Glamer Gifter

Flash
Flying
When this creature enters, choose up to one other target creature. Until end of turn, that creature has base power and toughness 4/4 and gains all creature types.

Morningtide's Light

Exile any number of target creatures. At the beginning of the next end step, return those cards to the battlefield tapped under their owners' control.
Until your next turn, prevent all damage that would be dealt to you.
Exile Morningtide's Light.

Wanderwine Distracter

Whenever this creature becomes tapped, target creature an opponent controls gets -3/-0 until end of turn.

Temporal Cleansing

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
The owner of target nonland permanent puts it into their library second from the top or on the bottom.

Island

Gravelgill Scoundrel

Vigilance
Whenever this creature attacks, you may tap another untapped creature you control. If you do, this creature can't be blocked this turn.

Springleaf Drum

{T}, Tap an untapped creature you control: Add one mana of any color.

Sygg, Wanderbrine Shield

Sygg can't be blocked.
Whenever this creature transforms into Sygg, Wanderbrine Shield, target creature you control gains protection from each color until your next turn.
At the beginning of your first main phase, you may pay {U}. If you do, transform Sygg.

Sygg, Wanderwine Wisdom

Sygg can't be blocked.
Whenever this creature enters or transforms into Sygg, Wanderwine Wisdom, target creature gains "Whenever this creature deals combat damage to a player or planeswalker, draw a card" until end of turn.
At the beginning of your first main phase, you may pay {W}. If you do, transform Sygg.

Sygg, Wanderwine Wisdom // Sygg, Wanderbrine Shield

Mountain

Unexpected Assistance

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Draw three cards, then discard a card.

Personify

Exile target creature you control, then return that card to the battlefield under its owner's control. Create a 1/1 colorless Shapeshifter creature token with changeling. (It's every creature type.)