Elvish Archdruid

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

Timberwatch Elf

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

Priest of Titania

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

Gladecover Scout

Hexproof (This creature can't be the target of spells or abilities your opponents control.)

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.

Quest for Renewal

Whenever a creature you control becomes tapped, you may put a quest counter on Quest for Renewal.
As long as there are four or more quest counters on Quest for Renewal, untap all creatures you control during each other player's untap step.

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.

Imperious Perfect

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

Alpha Status

Enchant creature
Enchanted creature gets +2/+2 for each other creature on the battlefield that shares a creature type with it.

Essence Warden

Whenever another creature enters, you gain 1 life.

Wirewood Channeler

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

Elvish Mystic

Nissa's Chosen

If Nissa's Chosen would die, put it on the bottom of its owner's library instead.

Wirewood Lodge

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

Skyshroud Poacher

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

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.

Forest

Immaculate Magistrate

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

Llanowar Elves

Elvish Champion

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

Wirewood Pride

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

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.