Castle Garenbrig

Castle Garenbrig enters tapped unless you control a Forest.
{T}: Add {G}.
{2}{G}{G}, {T}: Add six {G}. Spend this mana only to cast creature spells or activate abilities of creatures.

Dwynen, Gilt-Leaf Daen

Reach
Other Elf creatures you control get +1/+1.
Whenever Dwynen, Gilt-Leaf Daen attacks, you gain 1 life for each attacking Elf you control.

Elvish Promenade

Create a 1/1 green Elf Warrior creature token for each Elf you control.

Imperious Perfect

Other Elves you control get +1/+1.
{G}, {T}: Create a 1/1 green Elf Warrior creature token.

Second Harvest

For each token you control, create a token that's a copy of that permanent.

Dwynen's Elite

When Dwynen's Elite enters, if you control another Elf, create a 1/1 green Elf Warrior creature token.

Yavimaya, Cradle of Growth

Each land is a Forest in addition to its other land types.

Elvish Champion

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

Circle of Dreams Druid

{T}: Add {G} for each creature you control.

Elvish Mystic

Parallel Lives

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.

Elven Ambush

Timberwatch Elf

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