Skinshifter

{G}: Choose one. Activate only once each turn.
• Until end of turn, this creature becomes a Rhino with base power and toughness 4/4 and gains trample.
• Until end of turn, this creature becomes a Bird with base power and toughness 2/2 and gains flying.
• Until end of turn, this creature becomes a Plant with base power and toughness 0/8.

Belbe's Armor

{X}, {T}: Target creature gets -X/+X until end of turn.

Orchard Warden

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

Slagwurm Armor

Equipped creature gets +0/+6.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery. This card enters unattached and stays on the battlefield if the creature leaves.)

Behind the Scenes

Creatures you control have skulk. (They can't be blocked by creatures with greater power.)
{4}{W}: Creatures you control get +1/+1 until end of turn.

Evolving Wilds

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Black Poplar Shaman

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 you control enters, you may return this card from your graveyard to your hand.

Deathsprout

Destroy target creature. Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Refuse to Yield

Target creature gets +2/+7 until end of turn. Untap it.

Oathsworn Giant

Vigilance
Other creatures you control get +0/+2 and have vigilance.

Timber Protector

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

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.

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.

Primal Rage

Creatures you control have trample. (A creature with trample can deal excess combat damage to the player or planeswalker it's attacking.)

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.

Rasaad yn Bashir

Each creature you control assigns combat damage equal to its toughness rather than its power.
Whenever Rasaad yn Bashir attacks, if you have the initiative, double the toughness of each creature you control until end of turn.
Choose a Background (You can have a Background as a second commander.)

Access Tunnel

{T}: Add {C}.
{3}, {T}: Target creature with power 3 or less can't be blocked this turn.

Treebeard, Gracious Host

Trample, ward {2}
When Treebeard enters, create two Food tokens.
Whenever you gain life, put that many +1/+1 counters on target Halfling or Treefolk.

Slaughter the Strong

Each player chooses any number of creatures they control with total power 4 or less, then sacrifices all other creatures they control.

Sandsteppe Citadel

This land enters tapped.
{T}: Add {W}, {B}, or {G}.

Unhallowed Phalanx

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.