Timberwatch Elf

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

Forest

Llanowar Elves

Fyndhorn Elves

Elvish Mystic

Taunting Elf

All creatures able to block Taunting Elf do so.

Priest of Titania

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

Lead the Stampede

Look at the top five cards of your library. You may reveal any number of creature cards from among them and put the revealed cards into your hand. Put the rest on the bottom of your library in any order.

Lys Alana Huntmaster

Whenever you cast an Elf spell, you may create a 1/1 green Elf Warrior creature token.