Elvish Eulogist

Sacrifice Elvish Eulogist: You gain 1 life for each Elf card in your graveyard.

Nissa Revane

+1: Search your library for a card named Nissa's Chosen, put it onto the battlefield, then shuffle.
+1: You gain 2 life for each Elf you control.
−7: Search your library for any number of Elf creature cards, put them onto the battlefield, then shuffle.

Winnower Patrol

Kinship — At the beginning of your upkeep, you may look at the top card of your library. If it shares a creature type with Winnower Patrol, you may reveal it. If you do, put a +1/+1 counter on Winnower Patrol.

Sol Ring

Elvish Archdruid

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

Voice of the Woods

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

Elvish Champion

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

Timberwatch Elf

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

Elvish Visionary

When Elvish Visionary enters the battlefield, draw a card.

Llanowar Elves

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.

Arcane Signet

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

Imperious Perfect

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

Essence Warden

Whenever another creature enters the battlefield, you gain 1 life.

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.)

Heritage Druid

Tap three untapped Elves you control: Add {G}{G}{G}.

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.

Joraga Warcaller

Multikicker {1}{G} (You may pay an additional {1}{G} any number of times as you cast this spell.)
Joraga Warcaller enters the battlefield 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.

Heedless One

Trample
Heedless One's power and toughness are each equal to the number of Elves on the battlefield.

Skyshroud Poacher

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

Wellwisher

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

Fauna Shaman

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

Yavimaya, Cradle of Growth

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

Lys Alana Huntmaster

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

Wirewood Channeler

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