Trollhide

Enchant creature
Enchanted creature gets +2/+2 and has "{1}{G}: Regenerate this creature." (The next time the creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Gyre Sage

Evolve (Whenever a creature you control enters, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)
{T}: Add {G} for each +1/+1 counter on Gyre Sage.

Druid's Deliverance

Prevent all combat damage that would be dealt to you this turn. Populate. (Create a token that's a copy of a creature token you control.)

Timberwatch Elf

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

Lure

Enchant creature
All creatures able to block enchanted creature do so.

Aspect of Hydra

Target creature gets +X/+X until end of turn, where X is your devotion to green. (Each {G} in the mana costs of permanents you control counts toward your devotion to green.)

Elvish Vanguard

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

Pendelhaven Elder

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

Back to Nature

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.

Paragon of Eternal Wilds

Other green creatures you control get +1/+1.
{G}, {T}: Another target green creature you control gains trample until end of turn. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Naturalize

Elven Riders

Elven Riders can't be blocked except by Walls and/or creatures with flying.

Titanic Growth

Target creature gets +4/+4 until end of turn.

Elvish Promenade

Create a 1/1 green Elf Warrior creature token for each Elf you control.

Defiant Elf

Staff of the Wild Magus

Whenever you cast a green spell or a Forest you control enters, you gain 1 life.

Forest

Heedless One

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

Tribal Unity

Creatures of the creature type of your choice get +X/+X until end of turn.

Arbor Colossus

Reach
{3}{G}{G}{G}: Monstrosity 3. (If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.)
When Arbor Colossus becomes monstrous, destroy target creature with flying an opponent controls.

Whip Silk

Enchant creature
Enchanted creature has reach. (It can block creatures with flying.)
{G}: Return Whip Silk to its owner's hand.

Everglove Courier

You may choose not to untap Everglove Courier during your untap step.
{2}{G}, {T}: Target Elf creature gets +2/+2 and has trample for as long as Everglove Courier remains tapped.

Ivy Lane Denizen

Whenever another green creature you control enters, put a +1/+1 counter on target creature.

Wirewood Hivemaster

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

Tribal Forcemage

Morph {1}{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.)
When Tribal Forcemage is turned face up, creatures of the creature type of your choice get +2/+2 and gain trample until end of turn.

Wellwisher

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

Wirewood Channeler

{T}: Add X mana of any one color, where X is the number of Elves on the battlefield.

Windstorm

Windstorm deals X damage to each creature with flying.

Dragon Fangs

Enchant creature
Enchanted creature gets +1/+1 and has trample.
When a creature with mana value 6 or greater enters, you may return Dragon Fangs from your graveyard to the battlefield attached to that creature.

Taunting Elf

All creatures able to block Taunting Elf do so.

Elvish Guidance

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional {G} for each Elf on the battlefield.

Biorhythm

Each player's life total becomes the number of creatures they control.

Predator's Rapport

Choose target creature you control. You gain life equal to that creature's power plus its toughness.

Lys Alana Huntmaster

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