Forest

Skullclamp

Equipped creature gets +1/-1.
Whenever equipped creature dies, draw two cards.
Equip {1}

Thelonite Monk

{T}, Sacrifice a green creature: Target land becomes a Forest. (This effect lasts indefinitely.)

Altar of Dementia

Sacrifice a creature: Target player mills cards equal to the sacrificed creature's power.

Elvish Reclaimer

This creature gets +2/+2 as long as there are three or more land cards in your graveyard.
{2}, {T}, Sacrifice a land: Search your library for a land card, put it onto the battlefield tapped, then shuffle.

Embodiment of Insight

Vigilance
Land creatures you control have vigilance.
Landfall — Whenever a land you control enters, you may have target land you control become a 3/3 Elemental creature with haste until end of turn. It's still a land.

Temur Charger

Morph—Reveal a green card in your hand. (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 this creature is turned face up, target creature gains trample until end of turn.

Staff of Titania

Equipped creature gets +X/+X, where X is the number of Forests you control.
Whenever equipped creature attacks, create a 1/1 green Forest Dryad land creature token. (It's affected by summoning sickness.)
Equip {3}

Waker of the Wilds

{X}{G}{G}: Put X +1/+1 counters on target land you control. That land becomes a 0/0 Elemental creature with haste. It's still a land.

Spike Tiller

This creature enters with three +1/+1 counters on it.
{2}, Remove a +1/+1 counter from this creature: Put a +1/+1 counter on target creature.
{2}, Remove a +1/+1 counter from this creature: Target land becomes a 2/2 creature that's still a land. Put a +1/+1 counter on it.

Emergent Sequence

Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. That land becomes a 0/0 green and blue Fractal creature that's still a land. Put a +1/+1 counter on it for each land you had enter the battlefield under your control this turn.

Nissa, Worldwaker

+1: Target land you control becomes a 4/4 Elemental creature with trample. It's still a land.
+1: Untap up to four target Forests.
−7: Search your library for any number of basic land cards, put them onto the battlefield, then shuffle. Those lands become 4/4 Elemental creatures with trample. They're still lands.

Tempt with Discovery

Tempting offer — Search your library for a land card and put it onto the battlefield. Each opponent may search their library for a land card and put it onto the battlefield. For each opponent who searches a library this way, search your library for a land card and put it onto the battlefield. Then each player who searched a library this way shuffles.

Krosan Wayfarer

Sacrifice this creature: You may put a land card from your hand onto the battlefield.

Druid Class

(Gain the next level as a sorcery to add its ability.)
Landfall — Whenever a land you control enters, you gain 1 life.
{2}{G}: Level 2
You may play an additional land on each of your turns.
{4}{G}: Level 3
When this Class becomes level 3, target land you control becomes a creature with haste and "This creature's power and toughness are each equal to the number of lands you control." It's still a land.

Gobbling Ooze

{G}, Sacrifice another creature: Put a +1/+1 counter on this creature.

Sakura-Tribe Elder

Sacrifice this creature: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Wood Elves

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

Living Plane

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

Scute Swarm

Landfall — Whenever a land you control enters, create a 1/1 green Insect creature token. If you control six or more lands, create a token that's a copy of this creature instead.

Groundbreaker

Trample, haste
At the beginning of the end step, sacrifice this creature.

Veteran Explorer

When this creature dies, each player may search their library for up to two basic land cards, put them onto the battlefield, then shuffle.

Neverwinter Dryad

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

Primal Adversary

Trample
When this creature enters, you may pay {1}{G} any number of times. When you pay this cost one or more times, put that many +1/+1 counters on this creature, then up to that many target lands you control become 3/3 Wolf creatures with haste that are still lands.

Living Lands

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

Liege of the Tangle

Trample
Whenever this creature deals combat damage to a player, you may choose any number of target lands you control and put an awakening counter on each of them. Each of those lands is an 8/8 green Elemental creature for as long as it has an awakening counter on it. They're still lands.

Shamanic Revelation

Draw a card for each creature you control.
Ferocious — You gain 4 life for each creature you control with power 4 or greater.

Natural Affinity

All lands become 2/2 creatures until end of turn. They're still lands.

Uktabi Wildcats

Uktabi Wildcats's power and toughness are each equal to the number of Forests you control.
{G}, Sacrifice a Forest: Regenerate this creature.

Elvish Herder

{G}: Target creature gains trample until end of turn.

Nissa, Who Shakes the World

Whenever you tap a Forest for mana, add an additional {G}.
+1: Put three +1/+1 counters on up to one target noncreature land you control. Untap it. It becomes a 0/0 Elemental creature with vigilance and haste that's still a land.
−8: You get an emblem with "Lands you control have indestructible." Search your library for any number of Forest cards, put them onto the battlefield tapped, then shuffle.

Quirion Druid

{G}, {T}: Target land becomes a 2/2 green creature that's still a land. (This effect lasts indefinitely.)

Burnished Hart

{3}, Sacrifice this creature: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Heart Warden

{T}: Add {G}.
{2}, Sacrifice this creature: Draw a card.

Entish Restoration

Sacrifice a land. Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle. If you control a creature with power 4 or greater, instead search your library for up to three basic land cards, put them onto the battlefield tapped, then shuffle.

Dawntreader Elk

{G}, Sacrifice this creature: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Zuran Orb

Ashaya, Soul of the Wild

Ashaya'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.)

Boundless Realms

Search your library for up to X basic land cards, where X is the number of lands you control, put them onto the battlefield tapped, then shuffle.

Harrow

As an additional cost to cast this spell, sacrifice a land.
Search your library for up to two basic land cards, put them onto the battlefield, then shuffle.

Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

Kormus Bell

All Swamps are 1/1 black creatures that are still lands.

Yavimaya Elder

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

Haywire Mite

When this creature dies, you gain 2 life.
{G}, Sacrifice this creature: Exile target noncreature artifact or noncreature enchantment.

Cultivate

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.

Fertilid

This creature enters with two +1/+1 counters on it.
{1}{G}, Remove a +1/+1 counter from this creature: Target player searches their library for a basic land card, puts it onto the battlefield tapped, then shuffles.

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.)

Springbloom Druid

When this creature enters, you may sacrifice a land. If you do, search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Multani, Yavimaya's Avatar

Reach, trample
Multani 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.

Quirion Ranger

Return a Forest you control to its owner's hand: Untap target creature. Activate only once each turn.

Scryb Ranger

Flash
Flying, protection from blue
Return a Forest you control to its owner's hand: Untap target creature. Activate only once each turn.

Kamahl, Heart of Krosa

At the beginning of combat on your turn, creatures you control get +3/+3 and gain trample until end of turn.
{1}{G}: Until end of turn, target land you control becomes a 1/1 Elemental creature with vigilance, indestructible, and haste. It's still a land.
Partner (You can have two commanders if both have partner.)

Helix Pinnacle

Shroud (This enchantment can't be the target of spells or abilities.)
{X}: Put X tower counters on this enchantment.
At the beginning of your upkeep, if there are 100 or more tower counters on this enchantment, you win the game.

Sylvan Advocate

Vigilance
As long as you control six or more lands, this creature and land creatures you control get +2/+2.

Foundation Breaker

When this creature enters, you may destroy target artifact or enchantment.
Evoke {1}{G} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Tireless Tracker

Landfall — Whenever a land you control enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")
Whenever you sacrifice a Clue, put a +1/+1 counter on this creature.

Foratog

{G}, Sacrifice a Forest: This creature gets +2/+2 until end of turn.

Sylvan Awakening

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

Rude Awakening

Choose one —
• Untap all lands you control.
• Until end of turn, lands you control become 2/2 creatures that are still lands.
Entwine {2}{G} (Choose both if you pay the entwine cost.)

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.)

Bayou Groff

As an additional cost to cast this spell, sacrifice a creature or pay {3}.

Demonmail Hauberk

Equipped creature gets +4/+2.
Equip—Sacrifice a creature.

Nature's Revolt

All lands are 2/2 creatures that are still lands.

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.

Kamahl, Fist of Krosa

{G}: Target land becomes a 1/1 creature until end of turn. It's still a land.
{2}{G}{G}{G}: Creatures you control get +3/+3 and gain trample until end of turn.

Perilous Forays

{1}, Sacrifice a creature: Search your library for a land card with a basic land type, put it onto the battlefield tapped, then shuffle.

Magus of the Order

{G}, {T}, Sacrifice this creature and another green creature: Search your library for a green creature card, put it onto the battlefield, then shuffle.