Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Land Leeches

Gaea's Touch

{0}: You may put a basic Forest card from your hand onto the battlefield. Activate only as a sorcery and only once each turn.
Sacrifice Gaea's Touch: Add {G}{G}.

Mountain

Carnivorous Plant

Scarwood Goblins

Forest

Venom

Enchant creature
Whenever enchanted creature blocks or becomes blocked by a non-Wall creature, destroy the other creature at end of combat.

Goblin Wizard

{T}: You may put a Goblin permanent card from your hand onto the battlefield.
{R}: Target Goblin gains protection from white until end of turn.

Sisters of the Flame

People of the Woods

People of the Woods's toughness is equal to the number of Forests you control.

Maze of Ith

{T}: Untap target attacking creature. Prevent all combat damage that would be dealt to and dealt by that creature this turn.

Ball Lightning

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Haste (This creature can attack and {T} as soon as it comes under your control.)
At the beginning of the end step, sacrifice Ball Lightning.

Dark Sphere

{T}, Sacrifice Dark Sphere: The next time a source of your choice would deal damage to you this turn, prevent half that damage, rounded down.