Shriekwood Devourer

Trample
Whenever you attack with one or more creatures, untap up to X lands, where X is the greatest power among those creatures.

Seedguide Ash

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

Black Poplar Shaman

Heartwood Treefolk

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

Guardian of Cloverdell

When this creature enters, create three 1/1 white Kithkin Soldier creature tokens.
{G}, Sacrifice a Kithkin: You gain 1 life.

Great Forest Druid

Warden of the Woods

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

Ashnod's Altar

Orchard Strider

When this creature enters, create two Food tokens. (They're artifacts with "{2}, {T}, Sacrifice this token: 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.)

Willow Geist

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

Unstoppable Ash

Trample
Champion a Treefolk or Warrior (When this enters, sacrifice it unless you exile another Treefolk or Warrior you control. When this leaves the battlefield, that card returns to the battlefield.)
Whenever a creature you control becomes blocked, it gets +0/+5 until end of turn.

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.

Generous Ent

Reach
When this creature enters, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")
Forestcycling {1} ({1}, Discard this card: Search your library for a Forest card, reveal it, put it into your hand, then shuffle.)

Eternal Witness

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

Ghoultree

This spell costs {1} less to cast for each creature card in your graveyard.

Colfenor, the Last Yew

Vigilance, reach
Whenever Colfenor or another creature you control dies, return up to one other target creature card with lesser toughness from your graveyard to your hand.

Ferrafor, Young Yew

When Ferrafor enters, create a number of 1/1 green Saproling creature tokens equal to the number of counters among creatures target player controls.
{T}: Double the number of each kind of counter on target creature.

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 this enchantment.

Dormant Grove // Gnarled Grovestrider

Treefolk Harbinger

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

Orchard Warden

Whenever another Treefolk creature you control enters, you may gain life equal to that creature's toughness.

Weed-Pruner Poplar

At the beginning of your upkeep, target creature other than this creature gets -1/-1 until end of turn.

Fendeep Summoner

{T}: Up to two target Swamps each become 3/5 Treefolk Warrior creatures in addition to their other types until end of turn.

Battlewand Oak

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

Heartwood Storyteller

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

Faeburrow Elder

Vigilance
This creature gets +1/+1 for each color among permanents you control.
{T}: For each color among permanents you control, add one mana of that color.

Bosk Banneret

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

Spore Frog

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

Ulvenwald Observer

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

Blighted Blackthorn

Whenever this creature enters or attacks, you may blight 2. If you do, you draw a card and lose 1 life. (To blight 2, put two -1/-1 counters on a creature you control.)

Magnigoth Treefolk

Domain — For each basic land type among lands you control, this creature has landwalk of that type. (It can't be blocked as long as defending player controls a land of that type.)

Deadwood Treefolk

Vanishing 3 (This creature enters with three time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
When this creature enters or leaves the battlefield, return another target creature card from your graveyard to your hand.

Doran, the Siege Tower

Each creature assigns combat damage equal to its toughness rather than its power.

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 this creature.

Sapling Nursery

Affinity for Forests (This spell costs {1} less to cast for each Forest you control.)
Landfall — Whenever a land you control enters, create a 3/4 green Treefolk creature token with reach.
{1}{G}, Exile this enchantment: Treefolk and Forests you control gain indestructible until end of turn.

Leaf-Crowned Elder

Kinship — At the beginning of your upkeep, you may look at the top card of your library. If it shares a creature type with this creature, you may reveal it. If you do, you may play that card without paying its mana cost.

Timber Protector

Other Treefolk creatures you control get +1/+1.
Other Treefolk and Forests you control have indestructible.

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.

Great Oak Guardian

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

Moonlit Lamenter

This creature enters with a -1/-1 counter on it.
{1}{W}, Remove a counter from this creature: Draw a card. Activate only as a sorcery.

Weatherseed Treefolk

Trample
When this creature dies, return it to its owner's hand.

Black Oak of Odunos

Defender
{B}, Tap another untapped creature you control: This creature gets +1/+1 until end of turn.

Doran, Besieged by Time

Each creature spell you cast with toughness greater than its power costs {1} less to cast.
Whenever a creature you control attacks or blocks, it gets +X/+X until end of turn, where X is the difference between its power and toughness.

Ironroot Warlord

Ironroot Warlord's power is equal to the number of creatures you control.
{3}{G}{W}: Create a 1/1 white Soldier creature token.

Treefolk Seedlings

Treefolk Seedlings's toughness is equal to the number of Forests you control.

Nemata, Grove Guardian

{2}{G}: Create a 1/1 green Saproling creature token.
Sacrifice a Saproling: Saproling creatures get +1/+1 until end of turn.

Gnarlroot Pallbearer

Trample
When this creature enters, target creature gets +X/+X until end of turn, where X is the number of creature cards in your graveyard.

Reach
Whenever Six attacks, mill three cards. You may put a land card from among them into your hand.
During your turn, nonland permanent cards in your graveyard have retrace. (You may cast permanent cards from your graveyard by discarding a land card in addition to paying their other costs.)

Indomitable Ancients

Sapling of Colfenor

Indestructible
Whenever Sapling of Colfenor attacks, reveal the top card of your library. If it's a creature card, you gain life equal to that card's toughness, lose life equal to its power, then put it into your hand.

Reclamation Sage

When this creature enters, you may destroy target artifact or enchantment.

Nemata, Primeval Warden

Reach
If a creature an opponent controls would die, exile it instead. When you do, create a 1/1 green Saproling creature token.
{G}, Sacrifice a Saproling: Nemata gets +2/+2 until end of turn.
{1}{B}, Sacrifice two Saprolings: Draw a card.

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 enters, if it was kicked, create X 1/1 green Saproling creature tokens.

Ancient Lumberknot

Each creature you control with toughness greater than its power assigns combat damage equal to its toughness rather than its power.

Treefolk Mystic

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

Tend the Sprigs

Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Then if you control seven or more lands and/or Treefolk, create a 3/4 green Treefolk creature token with reach. (It can block creatures with flying.)

Quickbeam, Upstart Ent

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

Thorntooth Witch

Whenever you cast a Treefolk spell, you may have target creature get +3/-3 until end of turn.

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.