Have

Wirewood Herald

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

Forest

Tormod's Crypt

{T}, Sacrifice this artifact: Exile target player's graveyard.

Wellwisher

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

Multani's Acolyte

Echo {G}{G} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When this creature enters, draw a card.

Caller of the Claw

Flash
When this creature enters, create a 2/2 green Bear creature token for each nontoken creature put into your graveyard from the battlefield this turn.

Gempalm Strider

Cycling {2}{G}{G} ({2}{G}{G}, Discard this card: Draw a card.)
When you cycle this card, Elf creatures get +2/+2 until end of turn.

Tribal Forcemage

Morph {1}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When this creature is turned face up, creatures of the creature type of your choice get +2/+2 and gain trample until end of turn.

Quirion Ranger

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

Fyndhorn Elves

Naturalize

Timberwatch Elf

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

Llanowar Elves

Sylvan Messenger

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
When this creature enters, reveal the top four cards of your library. Put all Elf cards revealed this way into your hand and the rest on the bottom of your library in any order.

Serene Heart

Choke

Islands don't untap during their controllers' untap steps.

Priest of Titania

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

Wirewood Symbiote

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