Forest

Skarrg Guildmage

{R}{G}: Creatures you control gain trample until end of turn.
{1}{R}{G}: Target land you control becomes a 4/4 Elemental creature until end of turn. It's still a land.

Zendikar Farguide

Forestwalk (This creature can't be blocked as long as defending player controls a Forest.)

Burrowing

Enchant creature
Enchanted creature has mountainwalk. (It can't be blocked as long as defending player controls a Mountain.)

Omnath, Locus of Rage

Landfall — Whenever a land enters the battlefield under your control, create a 5/5 red and green Elemental creature token.
Whenever Omnath, Locus of Rage or another Elemental you control dies, Omnath deals 3 damage to any target.

Ashling the Pilgrim

{1}{R}: Put a +1/+1 counter on Ashling the Pilgrim. If this is the third time this ability has resolved this turn, remove all +1/+1 counters from Ashling the Pilgrim, and it deals that much damage to each creature and each player.

Groundbreaker

Trample, haste
At the beginning of the end step, sacrifice Groundbreaker.

Scorch Spitter

Whenever Scorch Spitter attacks, it deals 1 damage to the player or planeswalker it's attacking.

Nova Chaser

Trample
Champion an Elemental (When this enters the battlefield, sacrifice it unless you exile another Elemental you control. When this leaves the battlefield, that card returns to the battlefield.)

Avenger of Zendikar

When Avenger of Zendikar enters the battlefield, create a 0/1 green Plant creature token for each land you control.
Landfall — Whenever a land enters the battlefield under your control, you may put a +1/+1 counter on each Plant creature you control.

Tunnel Ignus

Whenever a land enters the battlefield under an opponent's control, if that player had another land enter the battlefield under their control this turn, Tunnel Ignus deals 3 damage to that player.

Leafkin Druid

{T}: Add {G}. If you control four or more creatures, add {G}{G} instead.

Grow from the Ashes

Kicker {2} (You may pay an additional {2} as you cast this spell.)
Search your library for a basic land card, put it onto the battlefield, then shuffle. If this spell was kicked, instead search your library for two basic land cards, put them onto the battlefield, then shuffle.

Overgrowth Elemental

When Overgrowth Elemental enters the battlefield, put a +1/+1 counter on another target Elemental you control.
Whenever another creature you control dies, you gain 1 life. If that creature was an Elemental, put a +1/+1 counter on Overgrowth Elemental.

Catalyst Elemental

Sacrifice Catalyst Elemental: Add {R}{R}.

Magmatic Force

At the beginning of each upkeep, Magmatic Force deals 3 damage to any target.

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.

Ivy Elemental

Ivy Elemental enters the battlefield with X +1/+1 counters on it.

Tangled Vale

Tangled Vale enters the battlefield tapped.
{T}: Add {G}.

Tangled Florahedron

Tangled Florahedron // Tangled Vale

Zendikar Incarnate

Zendikar Incarnate's power is equal to the number of lands you control.

Mountain

Rampant Growth

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

War Elemental

When War Elemental enters the battlefield, sacrifice it unless an opponent was dealt damage this turn.
Whenever an opponent is dealt damage, put that many +1/+1 counters on War Elemental.

Phylath, World Sculptor

When Phylath, World Sculptor enters the battlefield, create a 0/1 green Plant creature token for each basic land you control.
Landfall — Whenever a land enters the battlefield under your control, put four +1/+1 counters on target Plant you control.

Brushfire Elemental

Haste
Brushfire Elemental can't be blocked by creatures with power 2 or less.
Landfall — Whenever a land enters the battlefield under your control, Brushfire Elemental gets +2/+2 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.)

Nature's Lore

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

Panharmonicon

If an artifact or creature entering the battlefield causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Living Twister

{1}{R}, Discard a land card: Living Twister deals 2 damage to any target.
{G}: Return a tapped land you control to its owner's hand.

Living Hive

Trample
Whenever Living Hive deals combat damage to a player, create that many 1/1 green Insect creature tokens.

Brighthearth Banneret

Elemental spells and Warrior spells you cast cost {1} less to cast.
Reinforce 1—{1}{R} ({1}{R}, Discard this card: Put a +1/+1 counter on target creature.)

Creeping Trailblazer

Other Elementals you control get +1/+0.
{2}{R}{G}: Creeping Trailblazer gets +1/+1 until end of turn for each Elemental you control.

Phytotitan

When Phytotitan dies, return it to the battlefield tapped under its owner's control at the beginning of their next upkeep.

Magus of the Order

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

Soulbright Flamekin

{2}: Target creature gains trample until end of turn. If this is the third time this ability has resolved this turn, you may add {R}{R}{R}{R}{R}{R}{R}{R}.

Arc Runner

Haste (This creature can attack and {T} as soon as it comes under your control.)
At the beginning of the end step, sacrifice Arc Runner.

Thunderkin Awakener

Haste
Whenever Thunderkin Awakener attacks, choose target Elemental creature card in your graveyard with toughness less than Thunderkin Awakener's toughness. Return that card to the battlefield tapped and attacking. Sacrifice it at the beginning of the next end step.

Chlorophant

At the beginning of your upkeep, you may put a +1/+1 counter on Chlorophant.
Threshold — As long as seven or more cards are in your graveyard, Chlorophant has "At the beginning of your upkeep, you may put another +1/+1 counter on Chlorophant."

Sunflare Shaman

{1}{R}, {T}: Sunflare Shaman deals X damage to any target and X damage to itself, where X is the number of Elemental cards in your graveyard.

Forced Adaptation

Enchant creature
At the beginning of your upkeep, put a +1/+1 counter on enchanted creature.

Ball Lightning

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Haste (This creature can attack and {T} as soon as it comes under your control.)
At the beginning of the end step, sacrifice Ball Lightning.

Onslaught

Whenever you cast a creature spell, tap target creature.

Kodama's Reach

Runaway Steam-Kin

Whenever you cast a red spell, if Runaway Steam-Kin has fewer than three +1/+1 counters on it, put a +1/+1 counter on Runaway Steam-Kin.
Remove three +1/+1 counters from Runaway Steam-Kin: Add {R}{R}{R}.

Wakeroot Elemental

{G}{G}{G}{G}{G}: Untap target land you control. It becomes a 5/5 Elemental creature with haste. It's still a land. (This effect lasts as long as that land remains on the battlefield.)

Gruul Turf

Gruul Turf enters the battlefield tapped.
When Gruul Turf enters the battlefield, return a land you control to its owner's hand.
{T}: Add {R}{G}.

Cindervines

Whenever an opponent casts a noncreature spell, Cindervines deals 1 damage to that player.
{1}, Sacrifice Cindervines: Destroy target artifact or enchantment. Cindervines deals 2 damage to that permanent's controller.

Explosive Vegetation

Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Gift of Paradise

Enchant land
When Gift of Paradise enters the battlefield, you gain 3 life.
Enchanted land has "{T}: Add two mana of any one color."

Leafkin Avenger

{T}: Add {G} for each creature with power 4 or greater you control.
{7}{R}: Leafkin Avenger deals damage equal to its power to target player or planeswalker.

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Rushwood Elemental

Trample
At the beginning of your upkeep, you may put a +1/+1 counter on Rushwood Elemental.

Chandra, Novice Pyromancer

+1: Elementals you control get +2/+0 until end of turn.
−1: Add {R}{R}.
−2: Chandra, Novice Pyromancer deals 2 damage to any target.

Into the Wilds

At the beginning of your upkeep, look at the top card of your library. If it's a land card, you may put it onto the battlefield.

Sol Ring

Clan Guildmage

{1}{R}, {T}: Target creature can't block this turn.
{2}{G}, {T}: Target land you control becomes a 4/4 Elemental creature with haste until end of turn. It's still a land.

Chandra's Magmutt

{T}: Chandra's Magmutt deals 1 damage to target player or planeswalker.

Scald

Whenever a player taps an Island for mana, Scald deals 1 damage to that player.

Cinder Pyromancer

{T}: Cinder Pyromancer deals 1 damage to target player or planeswalker.
Whenever you cast a red spell, you may untap Cinder Pyromancer.

Lotus Cobra

Landfall — Whenever a land enters the battlefield under your control, add one mana of any color.

Monsoon

At the beginning of each player's end step, tap all untapped Islands that player controls and Monsoon deals X damage to the player, where X is the number of Islands tapped this way.

Lifeforce

Chandra's Embercat

{T}: Add {R}. Spend this mana only to cast an Elemental spell or a Chandra planeswalker spell.

Gruul Guildgate

Gruul Guildgate enters the battlefield tapped.
{T}: Add {R} or {G}.

Thundermare

Haste (This creature can attack and {T} as soon as it comes under your control.)
When Thundermare enters the battlefield, tap all other creatures.

Arni Slays the Troll

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Target creature you control fights up to one target creature you don't control.
II — Add {R}. Put two +1/+1 counters on up to one target creature you control.
III — You gain life equal to the greatest power among creatures you control.

Flamekin Harbinger

When Flamekin Harbinger enters the battlefield, you may search your library for an Elemental card, reveal it, then shuffle and put that card on top.

In Search of Greatness

At the beginning of your upkeep, you may cast a permanent spell from your hand with mana value equal to 1 plus the highest mana value among other permanents you control without paying its mana cost. If you don't, scry 1.

Smokebraider

{T}: Add two mana in any combination of colors. Spend this mana only to cast Elemental spells or activate abilities of Elementals.

Primal Beyond

As Primal Beyond enters the battlefield, you may reveal an Elemental card from your hand. If you don't, Primal Beyond enters the battlefield tapped.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast an Elemental spell or activate an ability of an Elemental.

Thicket Crasher

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Other Elementals you control have trample.