Wickerbough Elder

Wickerbough Elder enters with a -1/-1 counter on it.
{G}, Remove a -1/-1 counter from Wickerbough Elder: Destroy target artifact or enchantment.

Ezzaroot Channeler

Reach
Creature spells you cast cost {X} less to cast, where X is the amount of life you gained this turn.
{T}: You gain 2 life.

Colossification

Enchant creature
When Colossification enters, tap enchanted creature.
Enchanted creature gets +20/+20.

Sapseep Forest

({T}: Add {G}.)
Sapseep Forest enters tapped.
{G}, {T}: You gain 1 life. Activate only if you control two or more green permanents.

Introduction to Annihilation

Exile target nonland permanent. Its controller draws a card.

Primal Bellow

Target creature gets +1/+1 until end of turn for each Forest you control.

Dungrove Elder

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
Dungrove Elder's power and toughness are each equal to the number of Forests you control.

Neverwinter Dryad

{2}, Sacrifice Neverwinter Dryad: Search your library for a basic Forest card, put it onto the battlefield tapped, then shuffle.

Everbark Shaman

{T}, Exile a Treefolk card from your graveyard: Search your library for up to two Forest cards, put them onto the battlefield tapped, then shuffle.

Gnarled Professor

Trample
When Gnarled Professor enters, learn. (You may reveal a Lesson card you own from outside the game and put it into your hand, or discard a card to draw a card.)

Containment Breach

Destroy target artifact or enchantment. If its mana value is 2 or less, create a 1/1 black and green Pest creature token with "When this creature dies, you gain 1 life."

Yew Spirit

{2}{G}{G}: Yew Spirit gets +X/+X until end of turn, where X is its power.

Forest

Gnarled Sage

Reach (This creature can block creatures with flying.)
As long as you've drawn two or more cards this turn, Gnarled Sage gets +0/+2 and has vigilance. (Attacking doesn't cause it to tap.)

Orchard Strider

When Orchard Strider enters, create two Food tokens. (They're artifacts with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")
Basic landcycling {1}{G} ({1}{G}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Basic Conjuration

Look at the top six cards of your library. You may reveal a creature card from among them and put it into your hand. Put the rest on the bottom of your library in a random order. You gain 3 life.

Heartwood Storyteller

Whenever a player casts a noncreature spell, each of that player's opponents may draw a card.

Environmental Sciences

Search your library for a basic land card, reveal it, put it into your hand, then shuffle. You gain 2 life.

Ulvenwald Observer

Whenever a creature you control with toughness 4 or greater dies, draw a card.

Willow Geist

Trample
Whenever one or more cards leave your graveyard, put a +1/+1 counter on Willow Geist.
When Willow Geist dies, you gain life equal to its power.