Thelonite Druid

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

Thallid Devourer

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

Aeolipile

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

Forest

Thallid

At the beginning of your upkeep, put a spore counter on this creature.
Remove three spore counters from this creature: Create a 1/1 green Saproling creature token.

Feral Thallid

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

Spore Flower

At the beginning of your upkeep, put a spore counter on this creature.
Remove three spore counters from this creature: Prevent all combat damage that would be dealt this turn.

Fungal Bloom

{G}{G}: Put a spore counter on target Fungus.

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.

Elvish Farmer

At the beginning of your upkeep, put a spore counter on this creature.
Remove three spore counters from this creature: Create a 1/1 green Saproling creature token.
Sacrifice a Saproling: You gain 2 life.

Night Soil

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

Thorn Thallid

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