Fangorn, Tree Shepherd

Treefolk you control have vigilance.
Whenever one or more Treefolk you control attack, add twice that much {G}.
You don't lose unspent green mana as steps and phases end.

Arboria

Creatures can't attack a player unless that player cast a spell or put a nontoken permanent onto the battlefield during their last turn.

Overrun

Creatures you control get +3/+3 and gain trample until end of turn. (Each of those creatures can deal excess combat damage to the player or planeswalker it's attacking.)

Weatherseed Totem

{T}: Add {G}.
{2}{G}{G}{G}: Weatherseed Totem becomes a 5/3 green Treefolk artifact creature with trample until end of turn.
When Weatherseed Totem is put into a graveyard from the battlefield, if it was a creature, return this card to its owner's hand.

Great Oak Guardian

Flash (You may cast this spell any time you could cast an instant.)
Reach
When Great Oak Guardian enters, creatures target player controls get +2/+2 until end of turn. Untap them.

Warden of the Woods

Vigilance (Attacking doesn't cause this creature to tap.)
Whenever Warden of the Woods becomes the target of a spell or ability an opponent controls, you may draw two cards.

Mossbeard Ancient

Trample
When Mossbeard Ancient enters, you gain 5 life.

Gnarled Grovestrider

Vigilance
Other creatures you control have vigilance.

Dormant Grove

At the beginning of combat on your turn, put a +1/+1 counter on target creature you control. Then if that creature has toughness 6 or greater, transform Dormant Grove.

Dormant Grove // Gnarled Grovestrider

Quickbeam, Upstart Ent

Whenever Quickbeam, Upstart Ent or another Treefolk you control enters, up to two target creatures each get +2/+2 and gain trample until end of turn.

Jaheira's Respite

Search your library for up to X basic land cards, where X is the number of creatures attacking you, put those cards onto the battlefield tapped, then shuffle.
Prevent all combat damage that would be dealt this turn.

Lignify

Enchant creature
Enchanted creature is a Treefolk with base power and toughness 0/4 and loses all abilities.

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.)

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.)

Seedguide Ash

When Seedguide Ash dies, you may search your library for up to three Forest cards, put them onto the battlefield tapped, then shuffle.

Reach of Branches

Create a 2/5 green Treefolk Shaman creature token.
Whenever a Forest you control enters, you may return Reach of Branches from your graveyard to your hand.

Assemble the Entmoot

Creatures you control have reach.
Sacrifice Assemble the Entmoot: Create three tapped X/X green Treefolk creature tokens, where X is the amount of life you gained this turn. Put a reach counter on each of them.

Cloudcrown Oak

Reach (This creature can block creatures with flying.)

Three Visits

Search your library for a Forest card, put it onto the battlefield, then shuffle.

Sylvan Offering

Choose an opponent. You and that player each create an X/X green Treefolk creature token.
Choose an opponent. You and that player each create X 1/1 green Elf Warrior creature tokens.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Bosk Banneret

Treefolk spells and Shaman spells you cast cost {1} less to cast.

Treefolk Harbinger

When Treefolk Harbinger enters, you may search your library for a Treefolk or Forest card, reveal it, then shuffle and put that card on top.

Caged Sun

As Caged Sun enters, choose a color.
Creatures you control of the chosen color get +1/+1.
Whenever a land's ability causes you to add one or more mana of the chosen color, add one additional mana of that color.

Realmwalker

Changeling (This card is every creature type.)
As Realmwalker enters, choose a creature type.
You may look at the top card of your library any time.
You may cast creature spells of the chosen type from the top of your library.

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Lumberknot

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
Whenever a creature dies, put a +1/+1 counter on Lumberknot.

Scarwood Treefolk

Heartwood Treefolk

Forestwalk (This creature can't be blocked as long as defending player controls a Forest.)

Omnath, Locus of Mana

You don't lose unspent green mana as steps and phases end.
Omnath, Locus of Mana gets +1/+1 for each unspent green mana you have.

Unnatural Growth

At the beginning of each combat, double the power and toughness of each creature you control until end of turn.

Yedora, Grave Gardener

Whenever another nontoken creature you control dies, you may return it to the battlefield face down under its owner's control. It's a Forest land. (It has no other types or abilities.)

Moss Diamond

Moss Diamond enters tapped.
{T}: Add {G}.

Emerald Medallion

Green spells you cast cost {1} less to cast.

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.

Oakgnarl Warrior

Magnigoth Sentry

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Rowan Treefolk

Nature's Claim

Destroy target artifact or enchantment. Its controller gains 4 life.

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

Harrow

As an additional cost to cast this spell, sacrifice a land.
Search your library for up to two basic land cards, put them onto the battlefield, then shuffle.

Exploration

You may play an additional land on each of your turns.

Kodama's Reach

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Rootgrapple

Destroy target noncreature permanent. If you control a Treefolk, draw a card.

Battlewand Oak

Whenever a Forest you control enters, Battlewand Oak gets +2/+2 until end of turn.
Whenever you cast a Treefolk spell, Battlewand Oak gets +2/+2 until end of turn.

Traverse the Outlands

Search your library for up to X basic land cards, where X is the greatest power among creatures you control. Put those cards onto the battlefield tapped, then shuffle.

Argothian Treefolk

Prevent all damage that would be dealt to Argothian Treefolk by artifact sources.

Cultivate

Garruk's Uprising

When this enchantment enters, if you control a creature with power 4 or greater, draw a card.
Creatures you control have trample. (Each of those creatures can deal excess combat damage to the player or planeswalker it's attacking.)
Whenever a creature you control with power 4 or greater enters, draw a card.

Wild Growth

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional {G}.

Colossal Majesty

At the beginning of your upkeep, if you control a creature with power 4 or greater, draw a card.

Timberland Ancient

Reach, trample
Forestcycling {2} ({2}, Discard this card: Search your library for a Forest card, reveal it, put it into your hand, then shuffle.)

Krosan Grip

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Destroy target artifact or enchantment.

Treefolk Umbra

Enchant creature
Enchanted creature gets +0/+2 and assigns combat damage equal to its toughness rather than its power.
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Verdeloth the Ancient

Kicker {X} (You may pay an additional {X} as you cast this spell.)
Saproling creatures and other Treefolk creatures get +1/+1.
When Verdeloth the Ancient enters, if it was kicked, create X 1/1 green Saproling creature tokens.

Tilling Treefolk

When Tilling Treefolk enters, you may return up to two target land cards from your graveyard to your hand.

Prevent all combat damage that would be dealt this turn.

Treefolk Mystic

Whenever Treefolk Mystic blocks or becomes blocked by a creature, destroy all Auras attached to that creature.

Lifecrafter's Bestiary

At the beginning of your upkeep, scry 1.
Whenever you cast a creature spell, you may pay {G}. If you do, draw a card.

Explore

You may play an additional land this turn.
Draw a card.

Ghastbark Twins

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Ghastbark Twins can block an additional creature each combat.

Yew Spirit

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

Rootless Yew

When Rootless Yew dies, search your library for a creature card with power or toughness 6 or greater, reveal it, put it into your hand, then shuffle.