Wistful Selkie

Craterhoof Behemoth

Haste
When this creature enters, creatures you control gain trample and get +X/+X until end of turn, where X is the number of creatures you control.

Nylea's Disciple

When this creature enters, you gain life equal to your devotion to green. (Each {G} in the mana costs of permanents you control counts toward your devotion to green.)

Soul of the Harvest

Trample
Whenever another nontoken creature you control enters, you may draw a card.

Primeval Titan

Trample
Whenever this creature enters or attacks, you may search your library for up to two land cards, put them onto the battlefield tapped, then shuffle.

Eternal Witness

When this creature enters, you may return target card from your graveyard to your hand.

Birds of Paradise

Genesis Wave

Reveal the top X cards of your library. You may put any number of permanent cards with mana value X or less from among them onto the battlefield. Then put all cards revealed this way that weren't put onto the battlefield into your graveyard.

Tormod's Crypt

{T}, Sacrifice this artifact: Exile target player's graveyard.

Acidic Slime

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
When this creature enters, destroy target artifact, enchantment, or land.

Tireless Tracker

Landfall — Whenever a land you control enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")
Whenever you sacrifice a Clue, put a +1/+1 counter on this creature.

Aspect of Hydra

Target creature gets +X/+X until end of turn, where X is your devotion to green. (Each {G} in the mana costs of permanents you control counts toward your devotion to green.)

Primal Command

Choose two —
• Target player gains 7 life.
• Put target noncreature permanent on top of its owner's library.
• Target player shuffles their graveyard into their library.
• Search your library for a creature card, reveal it, put it into your hand, then shuffle.

Burning-Tree Emissary

Lair of the Hydra

If you control two or more other lands, this land enters tapped.
{T}: Add {G}.
{X}{G}: Until end of turn, this land becomes an X/X green Hydra creature. It's still a land. X can't be 0.

Utopia Sprawl

Enchant Forest
As this Aura enters, choose a color.
Whenever enchanted Forest is tapped for mana, its controller adds an additional one mana of the chosen color.

Mistcutter Hydra

This spell can't be countered.
Haste, protection from blue
This creature enters with X +1/+1 counters on it.

Arbor Elf

Old-Growth Troll

Trample
When Old-Growth Troll dies, if it was a creature, return it to the battlefield. It's an Aura enchantment with enchant Forest you control and "Enchanted Forest has '{T}: Add {G}{G}' and '{1}, {T}, Sacrifice this land: Create a tapped 4/4 green Troll Warrior creature token with trample.'"

Oath of Nissa

When Oath of Nissa enters, look at the top three cards of your library. You may reveal a creature, land, or planeswalker card from among them and put it into your hand. Put the rest on the bottom of your library in any order.
You may spend mana as though it were mana of any color to cast planeswalker spells.

Nykthos, Shrine to Nyx

{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

Garruk Wildspeaker

+1: Untap two target lands.
−1: Create a 3/3 green Beast creature token.
−4: Creatures you control get +3/+3 and gain trample until end of turn.

Forest

Corrosive Gale

({G/P} can be paid with either {G} or 2 life.)
Corrosive Gale deals X damage to each creature with flying.