Trumpeting Herd

Create a 3/3 green Elephant creature token.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Overcome

Creatures you control get +2/+2 and gain trample until end of turn. (Each of those creatures can deal excess combat damage to the player or planeswalker it's attacking.)

Squirrel Sanctuary

When Squirrel Sanctuary enters, create a 1/1 green Squirrel creature token.
Whenever a nontoken creature you control dies, you may pay {1}. If you do, return Squirrel Sanctuary to its owner's hand.

Prey Upon

Target creature you control fights target creature you don't control. (Each deals damage equal to its power to the other.)

Mother Bear

{3}{G}{G}, Exile Mother Bear from your graveyard: Create two 2/2 green Bear creature tokens. Activate only as a sorcery.

Glimmer Bairn

Sacrifice a token: Glimmer Bairn gets +2/+2 until end of turn.

Scurry Oak

Evolve (Whenever a creature you control enters, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)
Whenever one or more +1/+1 counters are put on Scurry Oak, you may create a 1/1 green Squirrel creature token.

Ferocious Pup

When Ferocious Pup enters, create a 2/2 green Wolf creature token.

Thriving Grove

Thriving Grove enters tapped. As it enters, choose a color other than green.
{T}: Add {G} or one mana of the chosen color.

Forest

Chitterspitter

At the beginning of your upkeep, you may sacrifice a token. If you do, put an acorn counter on Chitterspitter.
Squirrels you control get +1/+1 for each acorn counter on Chitterspitter.
{G}, {T}: Create a 1/1 green Squirrel creature token.

Bestial Menace

Create a 1/1 green Snake creature token, a 2/2 green Wolf creature token, and a 3/3 green Elephant creature token.

Woodland Champion

Whenever one or more tokens you control enter, put that many +1/+1 counters on Woodland Champion.