Forest

Spore Cloud

Tap all blocking creatures. Prevent all combat damage that would be dealt this turn. Each attacking creature and each blocking creature doesn't untap during its controller's next untap step.

Havenwood Battleground

Havenwood Battleground enters tapped.
{T}: Add {G}.
{T}, Sacrifice Havenwood Battleground: Add {G}{G}.

Thorn Thallid

At the beginning of your upkeep, put a spore counter on Thorn Thallid.
Remove three spore counters from Thorn Thallid: It deals 1 damage to any target.

Feral Thallid

At the beginning of your upkeep, put a spore counter on Feral Thallid.
Remove three spore counters from Feral Thallid: Regenerate Feral Thallid.

Thelonite Druid

{1}{G}, {T}, Sacrifice a creature: Forests you control become 2/3 creatures until end of turn. They're still lands.

Night Soil

{1}, Exile two creature cards from a single graveyard: Create a 1/1 green Saproling creature token.

Thallid Devourer

At the beginning of your upkeep, put a spore counter on Thallid Devourer.
Remove three spore counters from Thallid Devourer: Create a 1/1 green Saproling creature token.
Sacrifice a Saproling: Thallid Devourer gets +1/+2 until end of turn.

Aeolipile

{1}, {T}, Sacrifice Aeolipile: It deals 2 damage to any target.

Dwarven Ruins

Dwarven Ruins enters tapped.
{T}: Add {R}.
{T}, Sacrifice Dwarven Ruins: Add {R}{R}.

Dwarven Catapult

Dwarven Catapult deals X damage divided evenly, rounded down, among all creatures target opponent controls.