Timberwatch Elf

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

Elvish Vanguard

Whenever another Elf enters, put a +1/+1 counter on Elvish Vanguard.

Elvish Spirit Guide

Exile Elvish Spirit Guide from your hand: Add {G}.

Arbor Elf

Malachite Talisman

Whenever a player casts a green spell, you may pay {3}. If you do, untap target permanent.

Dwynen's Elite

When this creature enters, if you control another Elf, create a 1/1 green Elf Warrior creature token.

Gyre Sage

Evolve (Whenever a creature you control enters, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)
{T}: Add {G} for each +1/+1 counter on Gyre Sage.

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.

Talara's Battalion

Cast this spell only if you've cast another green spell this turn.
Trample

Elvish Mystic

Copperhorn Scout

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

Elvish Pioneer

When Elvish Pioneer enters, you may put a basic land card from your hand onto the battlefield tapped.

Hunting Triad

Create three 1/1 green Elf Warrior creature tokens.
Reinforce 3—{3}{G} ({3}{G}, Discard this card: Put three +1/+1 counters on target creature.)

Druid of the Cowl

Elvish Visionary

When Elvish Visionary enters, draw a card.

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.

Taunting Elf

All creatures able to block Taunting Elf do so.

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.)