Riverguard's Reflexes

Target creature gets +2/+2 and gains first strike until end of turn. Untap it.

Tributary Vaulter

Flying
Whenever this creature becomes tapped, another target Merfolk you control gets +2/+0 until end of turn.

Deepchannel Duelist

At the beginning of your end step, untap target Merfolk you control.
Other Merfolk you control get +1/+1.

Crib Swap

Changeling (This card is every creature type.)
Exile target creature. Its controller creates a 1/1 colorless Shapeshifter creature token with changeling.

Disruptor of Currents

Flash
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.)
When this creature enters, return up to one other target nonland permanent to its owner's hand.

Thirst for Identity

Draw three cards. Then discard two cards unless you discard a creature card.

Wanderbrine Trapper

{1}, {T}, Tap another untapped creature you control: Tap target creature an opponent controls.

Shore Lurker

Flying
When this creature enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Aquitect's Defenses

Flash
Enchant creature you control
When this Aura enters, enchanted creature gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)
Enchanted creature gets +1/+2.

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.

Plains

Springleaf Drum

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

Dawn-Blessed Pennant

As this artifact enters, choose Elemental, Elf, Faerie, Giant, Goblin, Kithkin, Merfolk, or Treefolk.
Whenever a permanent you control of the chosen type enters, you gain 1 life.
{2}, {T}, Sacrifice this artifact: Return target card of the chosen type from your graveyard to your hand.

Wanderwine Distracter

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

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.

Silvergill Peddler

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

Omni-Changeling

Changeling (This card is every creature type.)
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.)
You may have this creature enter as a copy of any creature on the battlefield, except it has changeling.

Blossombind

Enchant creature
When this Aura enters, tap enchanted creature.
Enchanted creature can't become untapped and can't have counters put on it.

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

Stalactite Dagger

When this Equipment enters, create a 1/1 colorless Shapeshifter creature token with changeling. (It's every creature type.)
Equipped creature gets +1/+1 and is all creature types.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Eclipsed Merrow

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

Wanderbrine Preacher

Whenever this creature becomes tapped, you gain 2 life.

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.)

Island

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.