Timberwatch Elf

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

Quirion Ranger

Return a Forest you control to its owner's hand: Untap target creature. Activate only once each turn.

Forest

Arbor Elf

Wirewood Herald

When Wirewood Herald dies, you may search your library for an Elf card, reveal that card, put it into your hand, then shuffle.

Fortitude

Enchant creature
Sacrifice a Forest: Regenerate enchanted creature.
When Fortitude is put into a graveyard from the battlefield, return Fortitude to its owner's hand.

Lothlórien Lookout

Whenever Lothlórien Lookout attacks, scry 1.

Three Visits

Search your library for a Forest card, put it onto the battlefield, then shuffle.

Chance-Met Elves

Whenever you scry, put a +1/+1 counter on Chance-Met Elves. This ability triggers only once each turn.

Priest of Titania

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

Llanowar Elves

Llanowar Empath

When Llanowar Empath enters, scry 2, then reveal the top card of your library. If it's a creature card, put it into your hand. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Seeker of Skybreak

Timbermaw Larva

Whenever Timbermaw Larva attacks, it gets +1/+1 until end of turn for each Forest you control.

Village Elder

{G}, {T}, Sacrifice a Forest: Regenerate target creature.

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.