Imaryll, Elfhame Elite

Whenever Imaryll, Elfhame Elite attacks, it gets +X/+X until end of turn, where X is the number of other Elves you control.
You may have Imaryll assign its combat damage as though it weren't blocked.

Leaf-Crowned Visionary

Other Elves you control get +1/+1.
Whenever you cast an Elf spell, you may pay {G}. If you do, draw a card.

Beast Whisperer

Whenever you cast a creature spell, draw a card.

Skemfar Avenger

Whenever another nontoken Elf or Berserker you control dies, you draw a card and you lose 1 life.

Birds of Paradise

Elvish Warmaster

Whenever one or more other Elves enter the battlefield under your control, create a 1/1 green Elf Warrior creature token. This ability triggers only once each turn.
{5}{G}{G}: Elves you control get +2/+2 and gain deathtouch until end of turn.

Regal Force

When Regal Force enters the battlefield, draw a card for each green creature you control.

Llanowar Elves

Tyvar the Bellicose

Whenever one or more Elves you control attack, they gain deathtouch until end of turn.
Each creature you control has "Whenever a mana ability of this creature resolves, put a number of +1/+1 counters on it equal to the amount of mana this creature produced. This ability triggers only once each turn."

Forest

Fauna Shaman

{G}, {T}, Discard a creature card: Search your library for a creature card, reveal it, put it into your hand, then shuffle.

Gaea's Cradle

{T}: Add {G} for each creature you control.

Assassin's Trophy

Destroy target permanent an opponent controls. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

Essence Warden

Whenever another creature enters the battlefield, you gain 1 life.

Craterhoof Behemoth

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

Heritage Druid

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

Nettle Sentinel

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

Elvish Clancaller

Other Elves you control get +1/+1.
{4}{G}{G}, {T}: Search your library for a card named Elvish Clancaller, put it onto the battlefield, then shuffle.

Grand Warlord Radha

Haste
Whenever one or more creatures you control attack, add that much mana in any combination of {R} and/or {G}. Until end of turn, you don't lose this mana as steps and phases end.

Priest of Titania

{T}: Add {G} for each Elf on the battlefield.

Emmara, Soul of the Accord

Whenever Emmara, Soul of the Accord becomes tapped, create a 1/1 white Soldier creature token with lifelink.