Frogify

Enchant creature
Enchanted creature loses all abilities and is a blue Frog creature with base power and toughness 1/1. (It loses all other card types and creature types.)

Mystical Dispute

This spell costs {2} less to cast if it targets a blue spell.
Counter target spell unless its controller pays {3}.

Didn't Say Please

Counter target spell. Its controller mills three cards.

Once and Future

Return target card from your graveyard to your hand. Put up to one other target card from your graveyard on top of your library. Exile Once and Future.
Adamant — If at least three green mana was spent to cast this spell, instead return those cards to your hand and exile Once and Future.

Thornwood Falls

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {G} or {U}.

Forest

Oko, Thief of Crowns

+2: Create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")
+1: Target artifact or creature loses all abilities and becomes a green Elk creature with base power and toughness 3/3.
−5: Exchange control of target artifact or creature you control and target creature an opponent controls with power 3 or less.

Trail of Crumbs

When Trail of Crumbs enters, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")
Whenever you sacrifice a Food, you may pay {1}. If you do, look at the top two cards of your library. You may reveal a permanent card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Midnight Clock

{T}: Add {U}.
{2}{U}: Put an hour counter on Midnight Clock.
At the beginning of each upkeep, put an hour counter on Midnight Clock.
When the twelfth hour counter is put on Midnight Clock, shuffle your hand and graveyard into your library, then draw seven cards. Exile Midnight Clock.

Venture Deeper

Target player mills four cards. (Then exile this card. You may cast the creature later from exile.)

Merfolk Secretkeeper

Merfolk Secretkeeper // Venture Deeper

Return to Nature

Choose one —
• Destroy target artifact.
• Destroy target enchantment.
• Exile target card from a graveyard.

Fierce Witchstalker

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
When Fierce Witchstalker enters, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")

Wicked Wolf

When Wicked Wolf enters, it fights up to one target creature you don't control.
Sacrifice a Food: Put a +1/+1 counter on Wicked Wolf. It gains indestructible until end of turn. Tap it.

Witching Well

When Witching Well enters, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)
{3}{U}, Sacrifice Witching Well: Draw two cards.

Treats to Share

Create a Food token. (Then exile this card. You may cast the creature later from exile. A Food token is an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")