The Walls of Ba Sing Se

Defender
Other permanents you control have indestructible.

Angelic Wall

Defender (This creature can't attack.)
Flying

Tree of Perdition

Defender
{T}: Exchange target opponent's life total with this creature's toughness.

Felothar the Steadfast

Each creature you control assigns combat damage equal to its toughness rather than its power.
Creatures you control can attack as though they didn't have defender.
{3}, {T}, Sacrifice another creature: Draw cards equal to the sacrificed creature's toughness, then discard cards equal to its power.

Consulate Skygate

Defender
Reach (This creature can block creatures with flying.)

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.

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.

Ghoultree

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

Weathered Sentinels

Defender, vigilance, reach, trample
This creature can attack players who attacked you during their last turn as though it didn't have defender.
Whenever this creature attacks, it gets +3/+3 and gains indestructible until end of turn.

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.

Inversion Behemoth

At the beginning of combat on your turn, switch the power and toughness of each of any number of target creatures 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.

Jaddi Lifestrider

When this creature enters, you may tap any number of untapped creatures you control. You gain 2 life for each creature tapped this way.

Bosk Banneret

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

Wall of Shards

Defender, flying
Cumulative upkeep—An opponent gains 1 life. (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)

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

Wall of Tanglecord

Defender
{G}: This creature gains reach until end of turn. (It can block creatures with flying.)

Doran, the Siege Tower

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

Indomitable Ancients

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.

Ancient Lumberknot

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

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.

Doom Weaver

Reach
Soulbond (You may pair this creature with another unpaired creature when either enters. They remain paired for as long as you control both of them.)
As long as Doom Weaver is paired with another creature, each of those creatures has "When this creature dies, draw cards equal to its power."

Ancient Stone Idol

Flash
This spell costs {1} less to cast for each attacking creature.
Trample
When this creature dies, create a 6/12 colorless Construct artifact creature token with trample.

Tree of Redemption

Defender
{T}: Exchange your life total with this creature's toughness.

Black Poplar Shaman

Timber Protector

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

Yavimaya Ancients

{G}: This creature gets +1/-2 until end of turn.

Sunscape Familiar

Defender (This creature can't attack.)
Green spells and blue spells you cast cost {1} less to cast.

Unhallowed Phalanx

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.

Realmwalker

Changeling (This card is every creature type.)
As this creature 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.

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.

Lignify

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

Overgrown Battlement

Defender
{T}: Add {G} for each creature you control with defender.

Orchard Warden

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

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.

Wall of Blossoms

Defender
When this creature enters, draw a card.

Wall of Vines

Defender (This creature can't attack.)
Reach (This creature can block creatures with flying.)

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.)

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.

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.

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.