Forest

Seafloor Oracle

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

Gift of Paradise

Enchant land
When Gift of Paradise enters, you gain 3 life.
Enchanted land has "{T}: Add two mana of any one color."

Tempest Caller

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

Rhonas's Monument

Green creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, target creature you control gets +2/+2 and gains trample until end of turn.

Vineshaper Mystic

When Vineshaper Mystic enters, put a +1/+1 counter on each of up to two target Merfolk you control.

Jace, Ingenious Mind-Mage

+1: Draw a card.
+1: Untap all creatures you control.
−9: Gain control of up to three target creatures.

Island

River Heralds' Boon

Put a +1/+1 counter on target creature and a +1/+1 counter on up to one target Merfolk.

Grasping Current

Return up to two target creatures to their owner's hand.
Search your library and/or graveyard for a card named Jace, Ingenious Mind-Mage, reveal it, and put it into your hand. If you searched your library this way, shuffle.

River Darter

River Darter can't be blocked by Dinosaurs.

Jace's Sentinel

As long as you control a Jace planeswalker, Jace's Sentinel gets +1/+0 and can't be blocked.

Crushing Canopy

Choose one —
• Destroy target creature with flying.
• Destroy target enchantment.

Jungle Delver

{3}{G}: Put a +1/+1 counter on Jungle Delver.

Woodland Stream

Woodland Stream enters tapped.
{T}: Add {G} or {U}.

Herald of Secret Streams

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

Unsummon

Return target creature to its owner's hand.

Headwater Sentries

Mist-Cloaked Herald

Deeproot Warrior

Whenever Deeproot Warrior becomes blocked, it gets +1/+1 until end of turn.

Shapers of Nature

{3}{G}: Put a +1/+1 counter on target creature.
{2}{U}, Remove a +1/+1 counter from a creature you control: Draw a card.

Kumena's Speaker

Kumena's Speaker gets +1/+1 as long as you control another Merfolk or an Island.

Shaper Apprentice

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

Fleet Swallower

Whenever Fleet Swallower attacks, target player mills half their library, rounded up.

Supreme Will

Choose one —
• Counter target spell unless its controller pays {3}.
• Look at the top four cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

Crashing Tide

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

Wind Strider

Flash (You may cast this spell any time you could cast an instant.)
Flying

Silvergill Adept

As an additional cost to cast this spell, reveal a Merfolk card from your hand or pay {3}.
When Silvergill Adept enters, draw a card.