Forest

Dwynen's Elite

When Dwynen's Elite enters the battlefield, if you control another Elf, create a 1/1 green Elf Warrior creature token.

Elvish Champion

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

Infernal Grasp

Destroy target creature. You lose 2 life.

Swamp

Abomination of Llanowar

Vigilance; menace (This creature can't be blocked except by two or more creatures.)
Abomination of Llanowar's power and toughness are each equal to the number of Elves you control plus the number of Elf cards in your graveyard.

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.

Skemfar Elderhall

Skemfar Elderhall enters the battlefield tapped.
{T}: Add {G}.
{2}{B}{B}{G}, {T}, Sacrifice Skemfar Elderhall: Up to one target creature you don't control gets -2/-2 until end of turn. Create two 1/1 green Elf Warrior creature tokens. Activate only as a sorcery.

Crippling Fear

Choose a creature type. Creatures that aren't of the chosen type get -3/-3 until end of turn.

Elvish Archdruid

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

Imperious Perfect

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

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.

Canopy Tactician

Other Elves you control get +1/+1.
{T}: Add {G}{G}{G}.

Shaman of the Pack

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

Elvish Promenade

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

Llanowar Elves

Marwyn, the Nurturer

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

Lair of the Hydra

If you control two or more other lands, Lair of the Hydra enters the battlefield tapped.
{T}: Add {G}.
{X}{G}: Until end of turn, Lair of the Hydra becomes an X/X green Hydra creature. It's still a land. X can't be 0.

Lathril, Blade of the Elves

Menace
Whenever Lathril, Blade of the Elves deals combat damage to a player, create that many 1/1 green Elf Warrior creature tokens.
{T}, Tap ten untapped Elves you control: Each opponent loses 10 life and you gain 10 life.

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.