Quickbeam, Upstart Ent

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

Old Man Willow

Old Man Willow's power and toughness are each equal to the number of lands you control.
Whenever Old Man Willow attacks, you may sacrifice another creature or a token. When you do, target creature an opponent controls gets -2/-2 until end of turn.

Pact of the Serpent

Choose a creature type. Target player draws X cards and loses X life, where X is the number of creatures they control of the chosen type.

Blossoming Bogbeast

Whenever Blossoming Bogbeast attacks, you gain 2 life. Then creatures you control gain trample and get +X/+X until end of turn, where X is the amount of life you gained this turn.

Ikra Shidiqi, the Usurper

Menace
Whenever a creature you control deals combat damage to a player, you gain life equal to that creature's toughness.
Partner (You can have two commanders if both have partner.)

Great Oak Guardian

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

Thorntooth Witch

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

Vanquisher's Banner

As Vanquisher's Banner enters the battlefield, choose a creature type.
Creatures you control of the chosen type get +1/+1.
Whenever you cast a creature spell of the chosen type, draw a card.

Ulvenwald Observer

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

Orchard Warden

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

Bushmeat Poacher

{1}, {T}, Sacrifice another creature: You gain life equal to the sacrificed creature's toughness. Draw a card.

Golgari Signet

Foul Renewal

Return target creature card from your graveyard to your hand. Target creature gets -X/-X until end of turn, where X is the toughness of the card returned this way.

Talisman of Resilience

{T}: Add {C}.
{T}: Add {B} or {G}. Talisman of Resilience deals 1 damage to you.

Veinwitch Coven

Menace
Whenever you gain life, you may pay {B}. If you do, return target creature card from your graveyard to your hand.

Willowdusk, Essence Seer

{1}, {T}: Choose another target creature. Put a number of +1/+1 counters on it equal to the amount of life you gained this turn or the amount of life you lost this turn, whichever is greater. Activate only as a sorcery.

Lignify

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

Moss Diamond

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

Bosk Banneret

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

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.)

Treefolk Harbinger

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

Go for the Throat

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.

Fruit of the First Tree

Enchant creature
When enchanted creature dies, you gain X life and draw X cards, where X is its toughness.

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.

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.

Command Tower

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

Assault Formation

Each creature you control assigns combat damage equal to its toughness rather than its power.
{G}: Target creature with defender can attack this turn as though it didn't have defender.
{2}{G}: Creatures you control get +0/+1 until end of turn.

Kalonian Twingrove

Kalonian Twingrove's power and toughness are each equal to the number of Forests you control.
When Kalonian Twingrove enters the battlefield, create a green Treefolk Warrior creature token with "This creature's power and toughness are each equal to the number of Forests you control."

Arcane Signet

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.

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Dauntless Dourbark

Dauntless Dourbark's power and toughness are each equal to the number of Forests you control plus the number of Treefolk you control.
Dauntless Dourbark has trample as long as you control another Treefolk.

Stinging Study

You draw X cards and you lose X life, where X is the mana value of a commander you own on the battlefield or in the command zone.

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.

Reach of Branches

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

Heartwood Storyteller

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

Forest

Ancient Lumberknot

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

Rootgrapple

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

Swamp

Beast Within

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

Momentous Fall

As an additional cost to cast this spell, sacrifice a creature.
You draw cards equal to the sacrificed creature's power, then you gain life equal to its toughness.

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.

Phyrexian Arena

At the beginning of your upkeep, you draw a card and you lose 1 life.

Unstoppable Ash

Trample
Champion a Treefolk or Warrior (When this enters the battlefield, 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.

Cultivate

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.

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.

Putrefy

Destroy target artifact or creature. It can't be regenerated.

Patriarch's Bidding

Each player chooses a creature type. Each player returns all creature cards of a type chosen this way from their graveyard to the battlefield.

Primordial Sage

Whenever you cast a creature spell, you may draw a card.

Mortality Spear

This spell costs {2} less to cast if you gained life this turn.
Destroy target nonland permanent.

Deadly Tempest

Destroy all creatures. Each player loses life equal to the number of creatures they controlled that were destroyed this way.

Colfenor's Urn

Whenever a creature with toughness 4 or greater is put into your graveyard from the battlefield, you may exile it.
At the beginning of the end step, if three or more cards have been exiled with Colfenor's Urn, sacrifice it. If you do, return those cards to the battlefield under their owner's control.

Timber Protector

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

Black Poplar Shaman

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

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 Leaf-Crowned Elder, you may reveal it. If you do, you may play that card without paying its mana cost.

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.

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

Abzan Beastmaster

At the beginning of your upkeep, draw a card if you control the creature with the greatest toughness or tied for the greatest toughness.

Rampant Growth

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

Sol Ring

Beast Whisperer

Whenever you cast a creature spell, draw a card.

Herald's Horn

As Herald's Horn enters the battlefield, choose a creature type.
Creature spells you cast of the chosen type cost {1} less to cast.
At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.

Crippling Fear

Choose a creature type. Creatures that aren't of the chosen type get -3/-3 until end of turn.