Elvish Vanguard

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

Fyndhorn Elves

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

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

When Elvish Visionary enters, draw a card.

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

You gain 5 life.
Ferocious — You gain 10 life instead if you control a creature with power 4 or greater.

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