Green Sun's Zenith

Search your library for a green creature card with mana value X or less, put it onto the battlefield, then shuffle. Shuffle Green Sun's Zenith into its owner's library.

Lys Alana Scarblade

{T}, Discard an Elf card: Target creature gets -X/-X until end of turn, where X is the number of Elves you control.

Forest

Emperor Crocodile

When you control no other creatures, sacrifice Emperor Crocodile.

Blightsoil Druid

Elvish Vanguard

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

Deadbridge Shaman

When Deadbridge Shaman dies, target opponent discards a card.

Heritage Druid

Tap three untapped Elves you control: Add {G}{G}{G}.

Lys Alana Huntmaster

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

Rancor

Enchant creature
Enchanted creature gets +2/+0 and has trample.
When Rancor is put into a graveyard from the battlefield, return Rancor to its owner's hand.

Swamp

Twisted Abomination

{B}: Regenerate Twisted Abomination.
Swampcycling {2} ({2}, Discard this card: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.)

Centaur Chieftain

Haste
Threshold — As long as seven or more cards are in your graveyard, Centaur Chieftain has "When Centaur Chieftain enters the battlefield, creatures you control get +1/+1 and gain trample until end of turn."

Shaman of the Pack

When Shaman of the Pack enters the battlefield, target opponent loses life equal to the number of Elves you control.

Llanowar Elves

Roots

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