Battlewand Oak

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

Timberland Ancient

Reach, trample
Forestcycling {2} ({2}, Discard this card: Search your library for a Forest card, reveal it, put it into your hand, then shuffle.)

Black Poplar Shaman

Weed-Pruner Poplar

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

Orchard Strider

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

Generous Ent

Reach
When Generous Ent enters, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: 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.)

Oakgnarl Warrior

Crabapple Cohort

Crabapple Cohort gets +1/+1 as long as you control another green creature.

Rootgrapple

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

Lignify

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