Vitaspore Thallid

At the beginning of your upkeep, put a spore counter on Vitaspore Thallid.
Remove three spore counters from Vitaspore Thallid: Create a 1/1 green Saproling creature token.
Sacrifice a Saproling: Target creature gains haste until end of turn.

Llanowar Dead

Deathbloom Thallid

When Deathbloom Thallid dies, create a 1/1 green Saproling creature token.

Tukatongue Thallid

When Tukatongue Thallid dies, create a 1/1 green Saproling creature token.

Thallid Germinator

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

Carrion Feeder

Carrion Feeder can't block.
Sacrifice a creature: Put a +1/+1 counter on Carrion Feeder.

Bloodflow Connoisseur

Sacrifice a creature: Put a +1/+1 counter on Bloodflow Connoisseur.

Thallid

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

Yavimaya Sapherd

When Yavimaya Sapherd enters the battlefield, create a 1/1 green Saproling creature token.

Moldgraf Scavenger

Delirium — Moldgraf Scavenger gets +3/+0 as long as there are four or more card types among cards in your graveyard.

Viscera Seer

Sacrifice a creature: Scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

Ashnod's Altar

Thallid Shell-Dweller

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

Deathspore Thallid

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

Slimefoot, the Stowaway

Whenever a Saproling you control dies, Slimefoot, the Stowaway deals 1 damage to each opponent and you gain 1 life.
{4}: Create a 1/1 green Saproling creature token.