Wild Mongrel

Discard a card: Wild Mongrel gets +1/+1 and becomes the color of your choice until end of turn.

Arrogant Wurm

Trample
Madness {2}{G} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Snag

You may discard a Forest card rather than pay this spell's mana cost.
Prevent all combat damage that would be dealt by unblocked creatures this turn.

Syncopate

Counter target spell unless its controller pays {X}. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Naturalize

Tormod's Crypt

{T}, Sacrifice Tormod's Crypt: Exile target player's graveyard.

Aquamoeba

Discard a card: Switch Aquamoeba's power and toughness until end of turn.

Forest

Krosan Reclamation

Target player shuffles up to two target cards from their graveyard into their library.
Flashback {1}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Obsessive Search

Draw a card.
Madness {U} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Giant Growth

Target creature gets +3/+3 until end of turn.

Roar of the Wurm

Create a 6/6 green Wurm creature token.
Flashback {3}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Basking Rootwalla

{1}{G}: Basking Rootwalla gets +2/+2 until end of turn. Activate only once each turn.
Madness {0} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Ray of Revelation

Destroy target enchantment.
Flashback {G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Brawn

Trample
As long as Brawn is in your graveyard and you control a Forest, creatures you control have trample.

Circular Logic

Counter target spell unless its controller pays {1} for each card in your graveyard.
Madness {U} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Careful Study

Wonder

Flying
As long as Wonder is in your graveyard and you control an Island, creatures you control have flying.