Birds of Paradise

Llanowar Elves

Mosswort Bridge

Hideaway 4 (When this land enters, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.)
Mosswort Bridge enters tapped.
{T}: Add {G}.
{G}, {T}: You may play the exiled card without paying its mana cost if creatures you control have total power 10 or greater.

Casal, Pathbreaker Owlbear

Vigilance, trample
When this creature transforms into Casal, Pathbreaker Owlbear, other legendary creatures you control get +2/+2 and gain trample until end of turn.
At the beginning of your upkeep, transform Doric.

Casal, Lurkwood Pathfinder

Vigilance
When Casal enters, search your library for a Forest card, put it onto the battlefield tapped, then shuffle.
Whenever Doric attacks, you may pay {1}{G}. If you do, transform her.

Casal, Lurkwood Pathfinder // Casal, Pathbreaker Owlbear

Elvish Mystic

Dryad Arbor

(Dryad Arbor isn't a spell, it's affected by summoning sickness, and it has "{T}: Add {G}.")

Tranquil Thicket

Tranquil Thicket enters tapped.
{T}: Add {G}.
Cycling {G} ({G}, Discard this card: Draw a card.)

Fyndhorn Elves

Forest

Oran-Rief, the Vastwood

Oran-Rief, the Vastwood enters tapped.
{T}: Add {G}.
{T}: Put a +1/+1 counter on each green creature that entered this turn.