Evolution Witness

{1}{G}: Adapt 2. (If this creature has no +1/+1 counters on it, put two +1/+1 counters on it.)
Whenever one or more +1/+1 counters are put on Evolution Witness, return target permanent card from your graveyard to your hand.

Elvish Branchbender

{T}: Until end of turn, target Forest becomes an X/X Treefolk creature in addition to its other types, where X is the number of Elves you control.

Priest of Titania

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

Lys Alana Huntmaster

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

Elvish Mystic

Roots of Wisdom

Mill three cards, then return a land card or Elf card from your graveyard to your hand. If you can't, draw a card. (To mill a card, put the top card of your library into your graveyard.)

Llanowar Elves

Forest

Llanowar Visionary

When Llanowar Visionary enters, draw a card.
{T}: Add {G}.

Wildheart Invoker

{8}: Target creature gets +5/+5 and gains trample until end of turn. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Elvish Visionary

When Elvish Visionary enters, draw a card.

Pendelhaven Elder

{T}: Each 1/1 creature you control gets +1/+2 until end of turn.

Jaspera Sentinel

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

Dwynen's Elite

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

Overrun

Creatures you control get +3/+3 and gain trample until end of turn. (Each of those creatures can deal excess combat damage to the player or planeswalker it's attacking.)