Timberwatch Elf

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

Forest

Birchlore Rangers

Tap two untapped Elves you control: Add one mana of any color.
Morph {G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Quirion Ranger

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

Distant Melody

Choose a creature type. Draw a card for each permanent you control of that type.

Nettle Sentinel

Nettle Sentinel doesn't untap during your untap step.
Whenever you cast a green spell, you may untap Nettle Sentinel.

Priest of Titania

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

Llanowar Elves

Lys Alana Huntmaster

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

Land Grant

If you have no land cards in hand, you may reveal your hand rather than pay this spell's mana cost.
Search your library for a Forest card, reveal that card, put it into your hand, then shuffle.

Jaspera Sentinel

Reach
{T}, Tap an untapped creature you control: Add one mana of any color.

Magnify

All creatures get +1/+1 until end of turn.

Elvish Mystic

Lead the Stampede

Look at the top five cards of your library. You may reveal any number of creature cards from among them and put the revealed cards into your hand. Put the rest on the bottom of your library in any order.

Wellwisher

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

Elvish Vanguard

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