Taunting Elf

All creatures able to block Taunting Elf do so.

Timberland Ruins

Timberland Ruins enters the battlefield tapped.
{T}: Add {G}.
{T}, Sacrifice Timberland Ruins: Add one mana of any color.

Forest

Wirewood Lodge

{T}: Add {C}.
{G}, {T}: Untap target Elf.

Elvish Herder

{G}: Target creature gains trample until end of turn.

Ambush Commander

Forests you control are 1/1 green Elf creatures that are still lands.
{1}{G}, Sacrifice an Elf: Target creature gets +3/+3 until end of turn.

Wellwisher

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

Elvish Vanguard

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

Heedless One

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

Yavimaya Barbarian

Elvish Lookout

Shroud (This creature can't be the target of spells or abilities.)

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.)

Llanowar Knight

Priest of Titania

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

Thornscape Battlemage

Kicker {R} and/or {W} (You may pay an additional {R} and/or {W} as you cast this spell.)
When Thornscape Battlemage enters the battlefield, if it was kicked with its {R} kicker, it deals 2 damage to any target.
When Thornscape Battlemage enters the battlefield, if it was kicked with its {W} kicker, destroy target artifact.

Fyndhorn Elves

Wirewood Symbiote

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

Skyshroud Elf

Wirewood Hivemaster

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

Timberwatch Elf

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

Elvish Champion

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

Llanowar Elite

Kicker {8} (You may pay an additional {8} as you cast this spell.)
Trample
If Llanowar Elite was kicked, it enters the battlefield with five +1/+1 counters on it.

Elvish Aberration

{T}: Add {G}{G}{G}.
Forestcycling {2} ({2}, Discard this card: Search your library for a Forest card, reveal it, put it into your hand, then shuffle.)

Gaea's Herald

Elfhame Palace

Elfhame Palace enters the battlefield tapped.
{T}: Add {G} or {W}.

Tolsimir Wolfblood

Other green creatures you control get +1/+1.
Other white creatures you control get +1/+1.
{T}: Create Voja, a legendary 2/2 green and white Wolf creature token.

Rancor

Enchant creature
Enchanted creature gets +2/+0 and has trample.
When Rancor is put into a graveyard from the battlefield, return Rancor to its owner's hand.

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.

Hunting Grounds

Threshold — As long as seven or more cards are in your graveyard, Hunting Grounds has "Whenever an opponent casts a spell, you may put a creature card from your hand onto the battlefield."

Skyshroud Poacher

{3}, {T}: Search your library for an Elf permanent card, put it onto the battlefield, then shuffle.