Elvish Champion

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

Roots

Enchant creature without flying
When Roots enters, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Prevent all combat damage that would be dealt this turn.
Cycling {2} ({2}, Discard this card: Draw a card.)

Prevent all combat damage that would be dealt this turn.
Each attacking creature doesn't untap during its controller's next untap step.

{1}{G}, Sacrifice Elf Replica: Destroy target enchantment.

{1}{G}, {T}: Target creature doesn't untap during its controller's next untap step.

{G}, {T}, Sacrifice Elvish Lyrist: Destroy target enchantment.

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

Trample
Heedless One's power and toughness are each equal to the number of Elves on the battlefield.

As Quirion Elves enters, choose a color.
{T}: Add {G}.
{T}: Add one mana of the chosen color.

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

Treetop Rangers can't be blocked except by creatures with flying.

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

Whenever another nontoken Elf enters, you may create a 1/1 green Insect creature token.