Some said killing the thallids only encouraged them.

The List

Night Soil

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

{1}, Exile two creature cards from a single graveyard: Put a 1/1 green Saproling creature token onto the battlefield.

The elves gathered huge piles of rot to grow fungus. Out of imitation or forethought, the thallids did the same.

{1}, Remove two creature cards in a single graveyard from the game: Put a 1/1 green Saproling creature token into play.

Some said killing the Thallids only encouraged them.

o1: Remove two creatures in any graveyard from the game to put a Saproling token into play. Treat this token as a 1/1 green creature.

The Elves gathered huge piles of rot to grow fungus. Out of imitation or forethought, the Thallids did the same.

"There were often more Thallids after a battle than before."
—*Sarpadian Empires, vol. III*