Arbor Elf

Timberwatch Elf

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

Ulamog's Crusher

Annihilator 2 (Whenever this creature attacks, defending player sacrifices two permanents of their choice.)
This creature attacks each combat if able.

Elvish Vanguard

Whenever another Elf enters, put a +1/+1 counter on this creature.

Forest

Wellwisher

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

Llanowar Elves

Elvish Visionary

Fyndhorn Elves

Quirion Ranger

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

Priest of Titania

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

Lys Alana Huntmaster

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

Elvish Mystic

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.

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.