Stonybrook Schoolmaster

Whenever this creature becomes tapped, you may create a 1/1 blue Merfolk Wizard creature token.

Tributary Vaulter

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

Moonsnare Prototype

{T}, Tap an untapped artifact or creature you control: Add {C}.
Channel — {4}{U}, Discard this card: The owner of target nonland permanent puts it on their choice of the top or bottom of their library.

Wanderbrine Preacher

Whenever this creature becomes tapped, you gain 2 life.

Stonybrook Banneret

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.

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.

Judge of Currents

Whenever a Merfolk you control becomes tapped, you may gain 1 life.

Springleaf Drum

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