Tower Defense

Creatures you control get +0/+5 and gain reach until end of turn.

Beast Within

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

Indomitable Ancients

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.

Command Tower

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

Forest

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.

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.)

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Plains

Arcane Signet

Last March of the Ents

This spell can't be countered.
Draw cards equal to the greatest toughness among creatures you control, then put any number of creature cards from your hand onto the battlefield.

Sol Ring

Tree of Perdition

Defender
{T}: Exchange target opponent's life total with Tree of Perdition's toughness.

Colfenor, the Last Yew

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

Bojuka Bog

Bojuka Bog enters tapped.
When Bojuka Bog enters, exile target player's graveyard.
{T}: Add {B}.

Swamp

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.

Indatha Triome

({T}: Add {W}, {B}, or {G}.)
Indatha Triome enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Trostani, Selesnya's Voice

Whenever another creature you control enters, you gain life equal to that creature's toughness.
{1}{G}{W}, {T}: Populate. (Create a token that's a copy of a creature token you control.)

Nature's Lore

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

Sandsteppe Citadel

Sandsteppe Citadel enters tapped.
{T}: Add {W}, {B}, or {G}.

Cultivate

Ancient Lumberknot

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

Doran, the Siege Tower

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

Three Visits

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

Stoneskin

Flash
Enchant creature
Enchanted creature gets +0/+10.

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.

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.

Orchard Warden

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

Treebeard, Gracious Host

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

Bedrock Tortoise

During your turn, creatures you control have hexproof.
Each creature you control with toughness greater than its power assigns combat damage equal to its toughness rather than its power.

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.