Everbark Shaman

{T}, Exile a Treefolk card from your graveyard: Search your library for up to two Forest cards, put them onto the battlefield tapped, then shuffle.

Baru, Fist of Krosa

Whenever a Forest enters, green creatures you control get +1/+1 and gain trample until end of turn.
Grandeur — Discard another card named Baru, Fist of Krosa: Create an X/X green Wurm creature token, where X is the number of lands you control.

Blanchwood Armor

Enchant creature
Enchanted creature gets +1/+1 for each Forest you control.

Awaken the Woods

Create X 1/1 green Forest Dryad land creature tokens. (They're affected by summoning sickness.)

Ambush Commander

Forests you control are 1/1 green Elf creatures that are still lands.
{1}{G}, Sacrifice an Elf: Target creature gets +3/+3 until end of turn.

Ashaya, Soul of the Wild

Ashaya, Soul of the Wild's power and toughness are each equal to the number of lands you control.
Nontoken creatures you control are Forest lands in addition to their other types. (They're still affected by summoning sickness.)

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.)

Kalonian Twingrove

Kalonian Twingrove's power and toughness are each equal to the number of Forests you control.
When Kalonian Twingrove enters, create a green Treefolk Warrior creature token with "This creature's power and toughness are each equal to the number of Forests you control."

Life and Limb

All Forests and all Saprolings are 1/1 green Saproling creatures and Forest lands in addition to their other types. (They're affected by summoning sickness.)

Dungrove Elder

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
Dungrove Elder's power and toughness are each equal to the number of Forests you control.

Castle Garenbrig

Castle Garenbrig enters tapped unless you control a Forest.
{T}: Add {G}.
{2}{G}{G}, {T}: Add six {G}. Spend this mana only to cast creature spells or activate abilities of creatures.

Glimpse the Core

Choose one —
• Search your library for a basic Forest card, put that card onto the battlefield tapped, then shuffle.
• Return target Cave card from your graveyard to the battlefield tapped.

Arbor Elf

Nature's Lore

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

Flourishing Bloom-Kin

Flourishing Bloom-Kin gets +1/+1 for each Forest you control.
Disguise {4}{G}
When Flourishing Bloom-Kin is turned face up, search your library for up to two Forest cards and reveal them. Put one of them onto the battlefield tapped and the other into your hand, then shuffle.

Neverwinter Dryad

{2}, Sacrifice Neverwinter Dryad: Search your library for a basic Forest card, put it onto the battlefield tapped, then shuffle.

Howl of the Night Pack

Create a 2/2 green Wolf creature token for each Forest you control.

Coiling Woodworm

Coiling Woodworm's power is equal to the number of Forests on the battlefield.

Land Grant

If you have no land cards in hand, you may reveal your hand rather than pay this spell's mana cost.
Search your library for a Forest card, reveal that card, put it into your hand, then shuffle.

Living Lands

All Forests are 1/1 creatures that are still lands.

Brawn

Trample
As long as Brawn is in your graveyard and you control a Forest, creatures you control have trample.