Arbor Colossus

Reach
{3}{G}{G}{G}: Monstrosity 3. (If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.)
When this creature becomes monstrous, destroy target creature with flying an opponent controls.

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.)

Lurking Predators

Whenever an opponent casts a spell, reveal the top card of your library. If it's a creature card, put it onto the battlefield. Otherwise, you may put that card on the bottom of your library.

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.

Spore Frog

Sacrifice this creature: Prevent all combat damage that would be dealt this turn.

Eternal Witness

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

Havenwood Battleground

This land enters tapped.
{T}: Add {G}.
{T}, Sacrifice this land: Add {G}{G}.

Roaring Primadox

At the beginning of your upkeep, return a creature you control to its owner's hand.

Karametra's Acolyte

{T}: Add an amount of {G} equal to your devotion to green. (Each {G} in the mana costs of permanents you control counts toward your devotion to green.)

Forest

Sylvan Primordial

Reach
When this creature enters, for each opponent, destroy target noncreature permanent that player controls. For each permanent destroyed this way, search your library for a Forest card and put that card onto the battlefield tapped. Then shuffle.

Wall of Roots

Defender
Put a -0/-1 counter on this creature: Add {G}. Activate only once each turn.

Overgrown Battlement

Defender
{T}: Add {G} for each creature you control with defender.

Primal Surge

Exile the top card of your library. If it's a permanent card, you may put it onto the battlefield. If you do, repeat this process.

Wild Pair

Whenever a creature enters, if you cast it from your hand, you may search your library for a creature card with the same total power and toughness, put it onto the battlefield, then shuffle.

Hickory Woodlot

This land enters tapped with two depletion counters on it.
{T}, Remove a depletion counter from this land: Add {G}{G}. If there are no depletion counters on this land, sacrifice it.