Urborg, Tomb of Yawgmoth

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

Razaketh, the Foulblooded

Flying, trample
Pay 2 life, Sacrifice another creature: Search your library for a card, put that card into your hand, then shuffle.

Windswept Heath

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

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.

Lys Alana Huntmaster

Whenever you cast an Elf spell, you may 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.

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.

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.)

Concordant Crossroads

Vivien, Champion of the Wilds

You may cast creature spells as though they had flash.
+1: Until your next turn, up to one target creature gains vigilance and reach.
−2: Look at the top three cards of your library. Exile one face down and put the rest on the bottom of your library in any order. For as long as it remains exiled, you may cast it if it's a creature spell.

Icon of Ancestry

As Icon of Ancestry enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
{3}, {T}: Look at the top three cards of your library. You may reveal a creature card of the chosen type from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

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.

Mox Diamond

If Mox Diamond would enter, you may discard a land card instead. If you do, put Mox Diamond onto the battlefield. If you don't, put it into its owner's graveyard.
{T}: Add one mana of any color.

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.

Belbe, Corrupted Observer

At the beginning of each postcombat main phase, the active player adds {C}{C} for each of your opponents who lost life this turn. (Damage causes loss of life.)

Undergrowth Stadium

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

Finale of Devastation

Search your library and/or graveyard for a creature card with mana value X or less and put it onto the battlefield. If you search your library this way, shuffle. If X is 10 or more, creatures you control get +X/+X and gain haste until end of turn.

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.

Assassin's Trophy

Destroy target permanent an opponent controls. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

Forest

Skullclamp

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

Imperious Perfect

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

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.)

Rishkar, Peema Renegade

When Rishkar, Peema Renegade enters, put a +1/+1 counter on each of up to two target creatures.
Each creature you control with a counter on it has "{T}: Add {G}."

Reclamation Sage

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

Heroic Intervention

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

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.)

Sylvan Library

At the beginning of your draw step, you may draw two additional cards. If you do, choose two cards in your hand drawn this turn. For each of those cards, pay 4 life or put the card on top of your library.

Rampant Growth

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

Phyrexian Reclamation

{1}{B}, Pay 2 life: Return target creature card from your graveyard to your hand.

Elvish Dreadlord

Deathtouch
When Elvish Dreadlord dies, non-Elf creatures get -3/-3 until end of turn.
Encore {5}{B}{B} ({5}{B}{B}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Wood Elves

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

Abrupt Decay

This spell can't be countered.
Destroy target nonland permanent with mana value 3 or less.

Snow-Covered Swamp

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}."

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.)

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.

Bayou

Elves of Deep Shadow

{T}: Add {B}. Elves of Deep Shadow deals 1 damage to you.

Herald's Horn

As Herald's Horn enters, choose a creature type.
Creature spells you cast of the chosen type cost {1} less to cast.
At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.

Arcane Signet

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

Kodama's Reach

Quirion Ranger

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

Overgrown Tomb

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

Phyrexian Tower

{T}: Add {C}.
{T}, Sacrifice a creature: Add {B}{B}.

Elvish Mystic

Nature's Lore

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

Hardened Scales

If one or more +1/+1 counters would be put on a creature you control, that many plus one +1/+1 counters are put on it instead.

Phyrexian Arena

At the beginning of your upkeep, you draw a card and you lose 1 life.

Mana Crypt

At the beginning of your upkeep, flip a coin. If you lose the flip, Mana Crypt deals 3 damage to you.
{T}: Add {C}{C}.

Vanquisher's Banner

As Vanquisher's Banner enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
Whenever you cast a creature spell of the chosen type, draw a card.

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.

Beast Whisperer

Whenever you cast a creature spell, draw a card.

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.)

Nightshade Harvester

Whenever a land an opponent controls enters, that player loses 1 life. Put a +1/+1 counter on Nightshade Harvester.

Deathrite Shaman

{T}: Exile target land card from a graveyard. Add one mana of any color.
{B}, {T}: Exile target instant or sorcery card from a graveyard. Each opponent loses 2 life.
{G}, {T}: Exile target creature card from a graveyard. You gain 2 life.

Gaea's Cradle

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

Worldly Tutor

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

Vampiric Tutor

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

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

War Room

{T}: Add {C}.
{3}, {T}, Pay life equal to the number of colors in your commanders' color identity: Draw a card.

The Great Henge

This spell costs {X} less to cast, where X is the greatest power among creatures you control.
{T}: Add {G}{G}. You gain 2 life.
Whenever a nontoken creature you control enters, put a +1/+1 counter on it and draw a card.

Sol Ring

Boreal Druid

Immaculate Magistrate

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

Elvish Archdruid

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

Cavern of Souls

As Cavern of Souls enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

Nature's Claim

Destroy target artifact or enchantment. Its controller gains 4 life.

Priest of Titania

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

Incubation Druid

{T}: Add one mana of any type that a land you control could produce. If Incubation Druid has a +1/+1 counter on it, add three mana of that type instead.
{3}{G}{G}: Adapt 3. (If this creature has no +1/+1 counters on it, put three +1/+1 counters on it.)

Elvish Promenade

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

Wooded Foothills

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

Llanowar Elves

Command Tower

Guardian Project

Whenever a nontoken creature you control enters, if it doesn't have the same name as another creature you control or a creature card in your graveyard, draw a card.

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.

Fauna Shaman

{G}, {T}, Discard a creature card: Search your library for a creature card, reveal it, put it into your hand, then shuffle.

Wirewood Lodge

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

Demonic Tutor

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

Misty Rainforest

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

Three Visits

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