Yavimaya, Cradle of Growth

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

Priest of Titania

{T}: Add {G} for each Elf on the battlefield.

Shaman of the Pack

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

Diabolic Intent

As an additional cost to cast this spell, sacrifice a creature.
Search your library for a card, put that card into your hand, then shuffle.

Elvish Harbinger

When Elvish Harbinger enters, you may search your library for an Elf card, reveal it, then shuffle and put that card on top.
{T}: Add one mana of any color.

Allosaurus Shepherd

This spell can't be countered.
Green spells you control can't be countered.
{4}{G}{G}: Until end of turn, each Elf creature you control has base power and toughness 5/5 and becomes a Dinosaur in addition to its other creature types.

Skemfar Avenger

Whenever another nontoken Elf or Berserker you control dies, you draw a card and you lose 1 life.

Woodland Cemetery

Woodland Cemetery enters tapped unless you control a Swamp or a Forest.
{T}: Add {B} or {G}.

Argothian Elder

Vampiric Tutor

Search your library for a card, then shuffle and put that card on top. You lose 2 life.

Gilt-Leaf Palace

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

Tainted Wood

{T}: Add {C}.
{T}: Add {B} or {G}. Activate only if you control a Swamp.

Imperious Perfect

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

Freyalise, Llanowar's Fury

+2: Create a 1/1 green Elf Druid creature token with "{T}: Add {G}."
−2: Destroy target artifact or enchantment.
−6: Draw a card for each green creature you control.
Freyalise, Llanowar's Fury can be your commander.

Bayou

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.

Command Tower

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

Nath of the Gilt-Leaf

At the beginning of your upkeep, you may have target opponent discard a card at random.
Whenever an opponent discards a card, you may create a 1/1 green Elf Warrior creature token.

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.

Joraga Warcaller

Multikicker {1}{G} (You may pay an additional {1}{G} any number of times as you cast this spell.)
Joraga Warcaller enters with a +1/+1 counter on it for each time it was kicked.
Other Elf creatures you control get +1/+1 for each +1/+1 counter on Joraga Warcaller.

Cabal Coffers

{2}, {T}: Add {B} for each Swamp you control.

Immaculate Magistrate

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

Elvish Champion

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

Skyshroud Poacher

{3}, {T}: Search your library for an Elf permanent card, put it onto the battlefield, then shuffle.

Grim Tutor

Search your library for a card, put that card into your hand, then shuffle. You lose 3 life.

Crop Rotation

As an additional cost to cast this spell, sacrifice a land.
Search your library for a land card, put that card onto the battlefield, then shuffle.

Nadier, Agent of the Duskenel

Whenever a token you control leaves the battlefield, put a +1/+1 counter on Nadier, Agent of the Duskenel.
When Nadier leaves the battlefield, create a number of 1/1 green Elf Warrior creature tokens equal to its power.
Partner (You can have two commanders if both have partner.)

Elvish Guidance

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional {G} for each Elf on the battlefield.

Wolverine Riders

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

Urza's Saga

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Urza's Saga gains "{T}: Add {C}."
II — Urza's Saga gains "{2}, {T}: Create a 0/0 colorless Construct artifact creature token with 'This creature gets +1/+1 for each artifact you control.'"
III — Search your library for an artifact card with mana cost {0} or {1}, put it onto the battlefield, then shuffle.

Witch's Cottage

({T}: Add {B}.)
Witch's Cottage enters tapped unless you control three or more other Swamps.
When Witch's Cottage enters untapped, you may put target creature card from your graveyard on top of your library.

Tyvar Kell

Elves you control have "{T}: Add {B}."
+1: Put a +1/+1 counter on up to one target Elf. Untap it. It gains deathtouch until end of turn.
0: Create a 1/1 green Elf Warrior creature token.
−6: You get an emblem with "Whenever you cast an Elf spell, it gains haste until end of turn and you draw two cards."

Mortuary Mire

Mortuary Mire enters tapped.
When Mortuary Mire enters, you may put target creature card from your graveyard on top of your library.
{T}: Add {B}.

Joraga Treespeaker

Level up {1}{G} ({1}{G}: Put a level counter on this. Level up only as a sorcery.)
LEVEL 1-4
1/2
{T}: Add {G}{G}.
LEVEL 5+
1/4
Elves you control have "{T}: Add {G}{G}."

Lys Alana Huntmaster

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

Worldly Tutor

Search your library for a creature card, reveal it, then shuffle and put the card on top.

Sylvan Scrying

Search your library for a land card, reveal it, put it into your hand, then shuffle.

Undergrowth Stadium

Undergrowth Stadium enters tapped unless you have two or more opponents.
{T}: Add {B} or {G}.

Wirewood Pride

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

Toxic Deluge

As an additional cost to cast this spell, pay X life.
All creatures get -X/-X until end of turn.

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.

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.

Elven Ambush

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

Elvish Archdruid

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

Taunting Elf

All creatures able to block Taunting Elf do so.

Golgari Rot Farm

Golgari Rot Farm enters tapped.
When Golgari Rot Farm enters, return a land you control to its owner's hand.
{T}: Add {B}{G}.

Llanowar Wastes

{T}: Add {C}.
{T}: Add {B} or {G}. Llanowar Wastes deals 1 damage to you.

Sylvan Offering

Choose an opponent. You and that player each create an X/X green Treefolk creature token.
Choose an opponent. You and that player each create X 1/1 green Elf Warrior creature tokens.

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.

Wellwisher

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

Parallel Lives

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.

Harald Unites the Elves

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Mill three cards. You may put an Elf or Tyvar card from your graveyard onto the battlefield.
II — Put a +1/+1 counter on each Elf you control.
III — Whenever an Elf you control attacks this turn, target creature an opponent controls gets -1/-1 until end of turn.

Wirewood Herald

When Wirewood Herald dies, you may search your library for an Elf card, reveal that card, put it into your hand, then shuffle.

Expedition Map

{2}, {T}, Sacrifice Expedition Map: Search your library for a land card, reveal it, put it into your hand, then shuffle.

Swamp

Command Beacon

{T}: Add {C}.
{T}, Sacrifice Command Beacon: Put your commander into your hand from the command zone.

Elderfang Venom

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

Damnation

Destroy all creatures. They can't be regenerated.

Path of Ancestry

Path of Ancestry enters 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.)

Elvish Promenade

Yavimaya Hollow

{T}: Add {C}.
{G}, {T}: Regenerate target creature.

Deathcap Glade

Deathcap Glade enters tapped unless you control two or more other lands.
{T}: Add {B} or {G}.

Bramblewood Paragon

Each other Warrior creature you control enters with an additional +1/+1 counter on it.
Each creature you control with a +1/+1 counter on it has trample.

Demonic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Twilight Mire

{T}: Add {C}.
{B/G}, {T}: Add {B}{B}, {B}{G}, or {G}{G}.

Shizo, Death's Storehouse

{T}: Add {B}.
{B}, {T}: Target legendary creature gains fear until end of turn. (It can't be blocked except by artifact creatures and/or black creatures.)

Timberwatch Elf

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

Oran-Rief, the Vastwood

Oran-Rief, the Vastwood enters tapped.
{T}: Add {G}.
{T}: Put a +1/+1 counter on each green creature that entered this turn.

Flourishing Defenses

Whenever a -1/-1 counter is put on a creature, you may create a 1/1 green Elf Warrior creature token.

Black Sun's Zenith

Put X -1/-1 counters on each creature. Shuffle Black Sun's Zenith into its owner's library.

Forest

Urborg, Tomb of Yawgmoth

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

Copperhorn Scout

Whenever Copperhorn Scout attacks, untap each other creature you control.

Wirewood Lodge

{T}: Add {C}.
{G}, {T}: Untap target Elf.

Imaryll, Elfhame Elite

Whenever Imaryll, Elfhame Elite attacks, it gets +X/+X until end of turn, where X is the number of other Elves you control.
You may have Imaryll assign its combat damage as though it weren't blocked.

Bojuka Bog

Bojuka Bog enters tapped.
When Bojuka Bog enters, exile target player's graveyard.
{T}: Add {B}.

Marwyn, the Nurturer

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

Devoted Druid

{T}: Add {G}.
Put a -1/-1 counter on Devoted Druid: Untap Devoted Druid.

Overgrown Tomb

({T}: Add {B} or {G}.)
As Overgrown Tomb enters, you may pay 2 life. If you don't, it enters tapped.

Coat of Arms

Each creature gets +1/+1 for each other creature on the battlefield that shares at least one creature type with it. (For example, if two Goblin Warriors and a Goblin Shaman are on the battlefield, each gets +2/+2.)

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.

Boseiju, Who Endures

{T}: Add {G}.
Channel — {1}{G}, Discard Boseiju, Who Endures: Destroy target artifact, enchantment, or nonbasic land an opponent controls. That player may search their library for a land card with a basic land type, put it onto the battlefield, then shuffle. This ability costs {1} less to activate for each legendary creature you control.

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.

Eladamri, Lord of Leaves

Other Elf creatures have forestwalk. (They can't be blocked as long as defending player controls a Forest.)
Other Elves have shroud. (They can't be the targets of spells or abilities.)

Guildless Commons

Guildless Commons enters tapped.
When Guildless Commons enters, return a land you control to its owner's hand.
{T}: Add {C}{C}.