Drove of Elves

Hexproof
Drove of Elves's power and toughness are each equal to the number of green permanents you control.

Elvish Champion

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

Elven Ambush

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

Craterhoof Behemoth

Haste
When Craterhoof Behemoth enters, creatures you control gain trample and get +X/+X until end of turn, where X is the number of creatures you control.

Forest

Allosaurus Shepherd

This spell can't be countered.
Green spells you control can't be countered.
{4}{G}{G}: Until end of turn, each Elf creature you control has base power and toughness 5/5 and becomes a Dinosaur in addition to its other creature types.

Yavimaya, Cradle of Growth

Each land is a Forest in addition to its other land types.

Llanowar Elves

Bramblewood Paragon

Each other Warrior creature you control enters with an additional +1/+1 counter on it.
Each creature you control with a +1/+1 counter on it has trample.

Imperious Perfect

Other Elves you control get +1/+1.
{G}, {T}: Create a 1/1 green Elf Warrior creature token.

Eladamri, Lord of Leaves

Other Elf creatures have forestwalk. (They can't be blocked as long as defending player controls a Forest.)
Other Elves have shroud. (They can't be the targets of spells or abilities.)

Wren's Run Vanquisher

As an additional cost to cast this spell, reveal an Elf card from your hand or pay {3}.
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Joraga Warcaller

Multikicker {1}{G} (You may pay an additional {1}{G} any number of times as you cast this spell.)
Joraga Warcaller enters with a +1/+1 counter on it for each time it was kicked.
Other Elf creatures you control get +1/+1 for each +1/+1 counter on Joraga Warcaller.

Overwhelming Stampede

Until end of turn, creatures you control gain trample and get +X/+X, where X is the greatest power among creatures you control.

Lys Alana Huntmaster

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

Elvish Archdruid

Other Elf creatures you control get +1/+1.
{T}: Add {G} for each Elf you control.

Fierce Empath

When Fierce Empath enters, you may search your library for a creature card with mana value 6 or greater, reveal it, put it into your hand, then shuffle.

Marwyn, the Nurturer

Whenever another Elf you control enters, put a +1/+1 counter on Marwyn, the Nurturer.
{T}: Add an amount of {G} equal to Marwyn's power.

Dwynen, Gilt-Leaf Daen

Reach
Other Elf creatures you control get +1/+1.
Whenever Dwynen, Gilt-Leaf Daen attacks, you gain 1 life for each attacking Elf you control.