Forest

Blanchwood Armor

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

Den Protector

Creatures with power less than Den Protector's power can't block it.
Megamorph {1}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)
When Den Protector is turned face up, return target card from your graveyard to your hand.

Deathmist Raptor

Deathtouch
Whenever a permanent you control is turned face up, you may return Deathmist Raptor from your graveyard to the battlefield face up or face down.
Megamorph {4}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)

Branch of Boseiju

Reach
Branch of Boseiju gets +1/+1 for each land you control.

Boseiju Reaches Skyward

(As this Saga enters and after your draw step, add a lore counter.)
I — Search your library for up to two basic Forest cards, reveal them, put them into your hand, then shuffle.
II — Put up to one target land card from your graveyard on top of your library.
III — Exile this Saga, then return it to the battlefield transformed under your control.

Boseiju Reaches Skyward // Branch of Boseiju

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.)

Fertile Footsteps

Search your library for a basic land card, put it onto the battlefield, then shuffle. (Then exile this card. You may cast the creature later from exile.)

Beanstalk Giant

Beanstalk Giant's power and toughness are each equal to the number of lands you control.

Beanstalk Giant // Fertile Footsteps

Ochre Jelly

Trample
Ochre Jelly enters with X +1/+1 counters on it.
Split — When Ochre Jelly dies, if it had two or more +1/+1 counters on it, create a token that's a copy of it at the beginning of the next end step. The token enters with half that many +1/+1 counters on it, rounded down.

Overrun

Creatures you control get +3/+3 and gain trample until end of turn. (Each of those creatures can deal excess combat damage to the player or planeswalker it's attacking.)

Ainok Survivalist

Megamorph {1}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)
When Ainok Survivalist is turned face up, destroy target artifact or enchantment an opponent controls.

Ulvenwald Hydra

Reach
Ulvenwald Hydra's power and toughness are each equal to the number of lands you control.
When Ulvenwald Hydra enters, you may search your library for a land card, put it onto the battlefield tapped, then shuffle.

Garruk's Packleader

Whenever another creature you control with power 3 or greater enters, you may draw a card.

Howl of the Night Pack

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

Salt Road Ambushers

Whenever another permanent you control is turned face up, if it's a creature, put two +1/+1 counters on it.
Megamorph {3}{G}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)

Temur War Shaman

When Temur War Shaman enters, manifest the top card of your library. (Put that card onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)
Whenever a permanent you control is turned face up, if it's a creature, you may have it fight target creature you don't control.

Experiment Twelve

Trample
Whenever Experiment Twelve or another creature you control is turned face up, put +1/+1 counters on that creature equal to its power.
Disguise {4}{G} (You may cast this card face down for {3} as a 2/2 creature with ward {2}. Turn it face up any time for its disguise cost.)

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Herd Migration

Domain — Create a 3/3 green Beast creature token for each basic land type among lands you control.
{1}{G}, Discard Herd Migration: Search your library for a basic land card, reveal it, put it into your hand, then shuffle. You gain 3 life.

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."

Wood Elves

When Wood Elves enters, search your library for a Forest card, put that card onto the battlefield, then shuffle.

Krosan Colossus

Morph {6}{G}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Broodhatch Nantuko

Whenever Broodhatch Nantuko is dealt damage, you may create that many 1/1 green Insect creature tokens.
Morph {2}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Hooded Hydra

Hooded Hydra enters with X +1/+1 counters on it.
When Hooded Hydra dies, create a 1/1 green Snake creature token for each +1/+1 counter on it.
Morph {3}{G}{G}
As Hooded Hydra is turned face up, put five +1/+1 counters on it.

Traproot Kami

Defender; reach (This creature can block creatures with flying.)
Traproot Kami's toughness is equal to the number of Forests on the battlefield.

Nantuko Vigilante

Morph {1}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When Nantuko Vigilante is turned face up, destroy target artifact or enchantment.

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.

Cultivate

Kenrith's Transformation

Enchant creature
When Kenrith's Transformation enters, draw a card.
Enchanted creature loses all abilities and is a green Elk creature with base power and toughness 3/3. (It loses all other card types and creature types.)

Oran-Rief Hydra

Trample
Landfall — Whenever a land you control enters, put a +1/+1 counter on Oran-Rief Hydra. If that land is a Forest, put two +1/+1 counters on Oran-Rief Hydra instead.

Soul's Majesty

Draw cards equal to the power of target creature you control.

Scaled Herbalist

{T}: You may put a land card from your hand onto the battlefield.

Threats Undetected

Search your library for up to four creature cards with different powers and reveal them. An opponent chooses two of those cards. Shuffle the chosen cards into your library and put the rest into your hand.

Colossal Majesty

At the beginning of your upkeep, if you control a creature with power 4 or greater, draw a card.

Printlifter Ooze

Deathtouch
Whenever Printlifter Ooze or another creature you control is turned face up, create a 0/0 green Ooze creature token with trample. The token enters with X +1/+1 counters on it, where X is the number of other creatures you control.
Disguise {3}{G}

Circle of Dreams Druid

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

Prevent all combat damage that would be dealt this turn.

Root Elemental

Morph {5}{G}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When Root Elemental is turned face up, you may put a creature card from your hand onto the battlefield.

Krosan Cloudscraper

At the beginning of your upkeep, sacrifice Krosan Cloudscraper unless you pay {G}{G}.
Morph {7}{G}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Garruk's Uprising

When this enchantment enters, if you control a creature with power 4 or greater, draw a card.
Creatures you control have trample. (Each of those creatures can deal excess combat damage to the player or planeswalker it's attacking.)
Whenever a creature you control with power 4 or greater enters, draw a card.

Beacon of Creation

Create a 1/1 green Insect creature token for each Forest you control. Shuffle Beacon of Creation into its owner's library.

Dryad Arbor

(Dryad Arbor isn't a spell, it's affected by summoning sickness, and it has "{T}: Add {G}.")

Multani, Yavimaya's Avatar

Reach, trample
Multani, Yavimaya's Avatar gets +1/+1 for each land you control and each land card in your graveyard.
{1}{G}, Return two lands you control to their owner's hand: Return Multani from your graveyard to your hand.

Traverse the Outlands

Search your library for up to X basic land cards, where X is the greatest power among creatures you control. Put those cards onto the battlefield tapped, then shuffle.

Skyshroud Ranger

{T}: You may put a land card from your hand onto the battlefield. Activate only as a sorcery.

Topiary Stomper

Vigilance (Attacking doesn't cause this creature to tap.)
When Topiary Stomper enters, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Topiary Stomper can't attack or block unless you control seven or more lands.

Acidic Slime

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
When Acidic Slime enters, destroy target artifact, enchantment, or land.

Genesis Hydra

When you cast this spell, reveal the top X cards of your library. You may put a nonland permanent card with mana value X or less from among them onto the battlefield. Then shuffle the rest into your library.
Genesis Hydra enters with X +1/+1 counters on it.

Molimo, Maro-Sorcerer

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Molimo, Maro-Sorcerer's power and toughness are each equal to the number of lands you control.

Dokai, Weaver of Life

{4}{G}{G}, {T}: Create an X/X green Elemental creature token, where X is the number of lands you control.

Budoka Gardener

{T}: You may put a land card from your hand onto the battlefield. If you control ten or more lands, flip Budoka Gardener.

Budoka Gardener // Dokai, Weaver of Life

Ulvenwald Behemoth

Trample, haste
Other creatures you control get +1/+1 and have trample and haste.

Ulvenwald Oddity

Trample, haste
{5}{G}{G}: Transform Ulvenwald Oddity.

Ulvenwald Oddity // Ulvenwald Behemoth

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.)

Primal Bellow

Target creature gets +1/+1 until end of turn for each Forest you control.

Strength of Cedars

Target creature gets +X/+X until end of turn, where X is the number of lands you control.

Seedguide Ash

When Seedguide Ash dies, you may search your library for up to three Forest cards, put them onto the battlefield tapped, then shuffle.

Oakgnarl Warrior

Charge Through

Target creature gains trample until end of turn.
Draw a card.

You Happen On a Glade

Choose one —
• Journey On — Search your library for up to two basic land cards, reveal them, put them into your hand, then shuffle.
• Make Camp — Return target permanent card from your graveyard to your hand.

Mosstodon

{1}: Target creature with power 5 or greater gains trample until end of turn.

Timbermaw Larva

Whenever Timbermaw Larva attacks, it gets +1/+1 until end of turn for each Forest you control.

Yavimaya Elder

When Yavimaya Elder dies, you may search your library for up to two basic land cards, reveal them, put them into your hand, then shuffle.
{2}, Sacrifice Yavimaya Elder: Draw a card.

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.

Sylvan Awakening

Until your next turn, all lands you control become 2/2 Elemental creatures with reach, indestructible, and haste. They're still lands.

Werewolf Pack Leader

Pack tactics — Whenever Werewolf Pack Leader attacks, if you attacked with creatures with total power 6 or greater this combat, draw a card.
{3}{G}: Until end of turn, Werewolf Pack Leader has base power and toughness 5/3, gains trample, and isn't a Human.

Nature's Lore

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

Froghemoth

Trample, haste
Whenever Froghemoth deals combat damage to a player, exile up to that many target cards from their graveyard. Put a +1/+1 counter on Froghemoth for each creature card exiled this way. You gain 1 life for each noncreature card exiled this way.