Yavimaya, Cradle of Growth

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

Wirewood Channeler

{T}: Add X mana of any one color, where X is the number of Elves on the battlefield.

Immaculate Magistrate

{T}: Put a +1/+1 counter on target creature for each Elf you control.

Poison the Cup

Destroy target creature. If this spell was foretold, scry 2.
Foretell {1}{B} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Putrefy

Destroy target artifact or creature. It can't be regenerated.

Shaman of the Pack

When Shaman of the Pack enters the battlefield, target opponent loses life equal to the number of Elves you control.

Marwyn, the Nurturer

Whenever another Elf enters the battlefield under your control, put a +1/+1 counter on Marwyn, the Nurturer.
{T}: Add an amount of {G} equal to Marwyn's power.

Pendelhaven Elder

{T}: Each 1/1 creature you control gets +1/+2 until end of turn.

Timberwatch Elf

{T}: Target creature gets +X/+X until end of turn, where X is the number of Elves on the battlefield.

Farhaven Elf

When Farhaven Elf enters the battlefield, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Imperious Perfect

Other Elves you control get +1/+1.
{G}, {T}: Create a 1/1 green Elf Warrior creature token.

Elvish Champion

Other Elf creatures get +1/+1 and have forestwalk. (They can't be blocked as long as defending player controls a Forest.)

Wood Elves

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

Prowess of the Fair

Whenever another nontoken Elf is put into your graveyard from the battlefield, you may create a 1/1 green Elf Warrior creature token.

Golgari Findbroker

When Golgari Findbroker enters the battlefield, return target permanent card from your graveyard to your hand.

Jagged-Scar Archers

Jagged-Scar Archers's power and toughness are each equal to the number of Elves you control.
{T}: Jagged-Scar Archers deals damage equal to its power to target creature with flying.

Springbloom Druid

When Springbloom Druid enters the battlefield, 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.

Myriad Landscape

Myriad Landscape enters the battlefield tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

Sol Ring

Jaspera Sentinel

Reach
{T}, Tap an untapped creature you control: Add one mana of any color.

Miara, Thorn of the Glade

Whenever Miara, Thorn of the Glade or another Elf you control dies, you may pay {1} and 1 life. If you do, draw a card.
Partner (You can have two commanders if both have partner.)

Mana Reflection

If you tap a permanent for mana, it produces twice as much of that mana instead.

Poison-Tip Archer

Reach (This creature can block creatures with flying.)
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Whenever another creature dies, each opponent loses 1 life.

Verdant Catacombs

{T}, Pay 1 life, Sacrifice Verdant Catacombs: Search your library for a Swamp or Forest card, put it onto the battlefield, then shuffle.

Jungle Hollow

Jungle Hollow enters the battlefield tapped.
When Jungle Hollow enters the battlefield, you gain 1 life.
{T}: Add {B} or {G}.

Harvest Season

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

Dwynen, Gilt-Leaf Daen

Reach
Other Elf creatures you control get +1/+1.
Whenever Dwynen, Gilt-Leaf Daen attacks, you gain 1 life for each attacking Elf you control.

Binding the Old Gods

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Destroy target nonland permanent an opponent controls.
II — Search your library for a Forest card, put it onto the battlefield tapped, then shuffle.
III — Creatures you control gain deathtouch until end of turn.

Moldervine Reclamation

Whenever a creature you control dies, you gain 1 life and draw a card.

Pride of the Perfect

Canopy Tactician

Other Elves you control get +1/+1.
{T}: Add {G}{G}{G}.

Gilt-Leaf Palace

As Gilt-Leaf Palace enters the battlefield, you may reveal an Elf card from your hand. If you don't, Gilt-Leaf Palace enters the battlefield tapped.
{T}: Add {B} or {G}.

Casualties of War

Choose one or more —
• Destroy target artifact.
• Destroy target creature.
• Destroy target enchantment.
• Destroy target land.
• Destroy target planeswalker.

Path of Ancestry

Path of Ancestry enters the battlefield tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Beast Whisperer

Whenever you cast a creature spell, draw a card.

Llanowar Elves

Tyvar the Bellicose

Whenever one or more Elves you control attack, they gain deathtouch until end of turn.
Each creature you control has "Whenever a mana ability of this creature resolves, put a number of +1/+1 counters on it equal to the amount of mana this creature produced. This ability triggers only once each turn."

Fecundity

Whenever a creature dies, that creature's controller may draw a card.

Pact of the Serpent

Choose a creature type. Target player draws X cards and loses X life, where X is the number of creatures they control of the chosen type.

Elderfang Ritualist

When Elderfang Ritualist dies, return another target Elf card from your graveyard to your hand.

Wolverine Riders

At the beginning of each upkeep, create a 1/1 green Elf Warrior creature token.
Whenever another Elf enters the battlefield under your control, you gain life equal to its toughness.

Oracle of Mul Daya

You may play an additional land on each of your turns.
Play with the top card of your library revealed.
You may play lands from the top of your library.

Fyndhorn Elves

Sylvan Messenger

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
When Sylvan Messenger enters the battlefield, reveal the top four cards of your library. Put all Elf cards revealed this way into your hand and the rest on the bottom of your library in any order.

Doubling Season

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.
If an effect would put one or more counters on a permanent you control, it puts twice that many of those counters on that permanent instead.

Elderfang Venom

Attacking Elves you control have deathtouch.
Whenever an Elf you control dies, each opponent loses 1 life and you gain 1 life.

Serpent's Soul-Jar

Whenever an Elf you control dies, exile it.
{T}, Pay 2 life: Until end of turn, you may cast a creature spell from among cards exiled with Serpent's Soul-Jar.

Llanowar Mentor

{G}, {T}, Discard a card: Create a 1/1 green Elf Druid creature token named Llanowar Elves. It has "{T}: Add {G}."

Lys Alana Scarblade

{T}, Discard an Elf card: Target creature gets -X/-X until end of turn, where X is the number of Elves you control.

Skemfar Elderhall

Skemfar Elderhall enters the battlefield tapped.
{T}: Add {G}.
{2}{B}{B}{G}, {T}, Sacrifice Skemfar Elderhall: Up to one target creature you don't control gets -2/-2 until end of turn. Create two 1/1 green Elf Warrior creature tokens. Activate only as a sorcery.

Forest

Ezuri, Renegade Leader

{G}: Regenerate another target Elf.
{2}{G}{G}{G}: Elf creatures you control get +3/+3 and gain trample until end of turn.

Ashnod's Altar

Swamp

Llanowar Tribe

Eyeblight Massacre

Non-Elf creatures get -2/-2 until end of turn.

Return Upon the Tide

Return target creature card from your graveyard to the battlefield. If it's an Elf, create two 1/1 green Elf Warrior creature tokens.
Foretell {3}{B} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Lys Alana Huntmaster

Whenever you cast an Elf spell, you may create a 1/1 green Elf Warrior creature token.

Elvish Warmaster

Whenever one or more other Elves enter the battlefield under your control, create a 1/1 green Elf Warrior creature token. This ability triggers only once each turn.
{5}{G}{G}: Elves you control get +2/+2 and gain deathtouch until end of turn.

Crown of Skemfar

Enchant creature
Enchanted creature gets +1/+1 for each Elf you control and has reach.
{2}{G}: Return Crown of Skemfar from your graveyard to your hand.

Numa, Joraga Chieftain

At the beginning of combat on your turn, you may pay {X}{X}. When you do, distribute X +1/+1 counters among any number of target Elves.
Partner (You can have two commanders if both have partner.)

Gaea's Cradle

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

Masked Admirers

When Masked Admirers enters the battlefield, draw a card.
Whenever you cast a creature spell, you may pay {G}{G}. If you do, return Masked Admirers from your graveyard to your hand.

Wellwisher

{T}: You gain 1 life for each Elf on the battlefield.

Lathril, Blade of the Elves

Menace
Whenever Lathril, Blade of the Elves deals combat damage to a player, create that many 1/1 green Elf Warrior creature tokens.
{T}, Tap ten untapped Elves you control: Each opponent loses 10 life and you gain 10 life.

Skemfar Shadowsage

When Skemfar Shadowsage enters the battlefield, choose one —
• Each opponent loses X life, where X is the greatest number of creatures you control that have a creature type in common.
• You gain X life, where X is the greatest number of creatures you control that have a creature type in common.

Arcane Signet

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

Elvish Archdruid

Other Elf creatures you control get +1/+1.
{T}: Add {G} for each Elf you control.

Rhys the Exiled

Whenever Rhys the Exiled attacks, you gain 1 life for each Elf you control.
{B}, Sacrifice an Elf: Regenerate Rhys the Exiled.

Elven Ambush

Create a 1/1 green Elf Warrior creature token for each Elf you control.

Bounty of Skemfar

Reveal the top six cards of your library. You may put a land card from among them onto the battlefield tapped and an Elf card from among them into your hand. Put the rest on the bottom of your library in a random order.

Reclamation Sage

When Reclamation Sage enters the battlefield, you may destroy target artifact or enchantment.

Leaf-Crowned Visionary

Other Elves you control get +1/+1.
Whenever you cast an Elf spell, you may pay {G}. If you do, draw a card.

Voice of the Woods

Tap five untapped Elves you control: Create a 7/7 green Elemental creature token with trample.

Elvish Promenade

Abomination of Llanowar

Vigilance; menace (This creature can't be blocked except by two or more creatures.)
Abomination of Llanowar's power and toughness are each equal to the number of Elves you control plus the number of Elf cards in your graveyard.

Swarm Guildmage

{4}{B}, {T}: Creatures you control get +1/+0 and gain menace until end of turn. (They can't be blocked except by two or more creatures.)
{1}{G}, {T}: You gain 2 life.

Command Tower

Elvish Mystic

Nullmage Shepherd

Tap four untapped creatures you control: Destroy target artifact or enchantment.

Gaea's Anthem

Harald, King of Skemfar

Menace (This creature can't be blocked except by two or more creatures.)
When Harald, King of Skemfar enters the battlefield, look at the top five cards of your library. You may reveal an Elf, Warrior, or Tyvar card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Ruthless Winnower

At the beginning of each player's upkeep, that player sacrifices a non-Elf creature.