Burning-Tree Emissary

When Burning-Tree Emissary enters the battlefield, add {R}{G} to your mana pool.

Scavenging Ooze

{G}: Exile target card from a graveyard. If it was a creature card, put a +1/+1 counter on Scavenging Ooze and you gain 1 life.

Elvish Mystic

{T}: Add {G} to your mana pool.

Yavimaya Coast

{T}: Add {1} to your mana pool. {T}: Add {G} or {U} to your mana pool. Yavimaya Coast deals 1 damage to you.

Nykthos, Shrine to Nyx

{T}: Add {1} to your mana pool. {2}, {T}: Choose a color. Add to your mana pool 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.)

Nylea's Disciple

When Nylea's Disciple enters the battlefield, 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.)

Polukranos, World Eater

{X}{X}{G}: Monstrosity X. (If this creature isn't monstrous, put X +1/+1 counters on it and it becomes monstrous.) When Polukranos, World Eater becomes monstrous, it deals X damage divided as you choose among any number of target creatures your opponents control. Each of those creatures deals damage equal to its power to Polukranos.

Sylvan Caryatid

Defender, hexproof {T}: Add one mana of any color to your mana pool.

Llanowar Elves

Tap to add green mana to your mana pool. This tap can be played as an interrupt.

Oath of Nissa

Botanical Sanctum

Walking Ballista

Hydroid Krasis

When you cast this spell, you gain half X life and draw half X cards. Round down each time. Flying, trample Hydroid Krasis enters the battlefield with X +1/+1 counters on it.

Breeding Pool

({T}: Add {G} or {U}.) As Breeding Pool enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Nissa, Who Shakes the World

Whenever you tap a Forest for mana, add an additional {G}. +1: Put three +1/+1 counters on up to one target noncreature land you control. Untap it. It becomes a 0/0 Elemental creature with vigilance and haste that's still a land. −8: You get an emblem with "Lands you control have indestructible." Search your library for any number of Forest cards, put them onto the battlefield tapped, then shuffle your library.

Leyline of Abundance

If Leyline of Abundance is in your opening hand, you may begin the game with it on the battlefield. Whenever you tap a creature for mana, add an additional {G}. {6}{G}{G}: Put a +1/+1 counter on each creature you control.

Veil of Summer

Draw a card if an opponent has cast a blue or black spell this turn. Spells you control can't be countered this turn. You and permanents you control gain hexproof from blue and from black until end of turn. (You and they can't be the targets of blue or black spells or abilities your opponents control.)

Voracious Hydra

Trample Voracious Hydra enters the battlefield with X +1/+1 counters on it. When Voracious Hydra enters the battlefield, choose one — • Double the number of +1/+1 counters on Voracious Hydra. • Voracious Hydra fights target creature you don't control.

Once Upon a Time

If this spell is the first spell you've cast this game, you may cast it without paying its mana cost. Look at the top five cards of your library. You may reveal a creature or land card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

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.

Forest

({T}: Add {G}.)