Timberwatch Elf

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

Naturalize

Presence of Gond

Enchant creature
Enchanted creature has "{T}: Create a 1/1 green Elf Warrior creature token."

Lys Alana Huntmaster

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

Wirewood Pride

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

Forest

Elvish Vanguard

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

Elvish Mystic

Elvish Visionary

When Elvish Visionary enters the battlefield, draw a card.

Elven Farsight

Scry 3, then you may reveal the top card of your library. If it's a creature card, draw a card.

Llanowar Elves

Taunting Elf

All creatures able to block Taunting Elf do so.

Thornweald Archer

Defiant Elf

Echoing Courage

Target creature and all other creatures with the same name as that creature get +2/+2 until end of turn.

Aspect of Hydra

Target creature gets +X/+X until end of turn, where X is your devotion to green. (Each {G} in the mana costs of permanents you control counts toward your devotion to green.)