Evolving Door

{1}, {T}, Sacrifice a creature: Count the colors of the sacrificed creature, then search your library for a creature card that's exactly that many colors plus one. Exile that card, then shuffle. You may cast the exiled card. Activate only as a sorcery.

Night Soil

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

Vivien on the Hunt

+2: You may sacrifice a creature. If you do, search your library for a creature card with mana value equal to 1 plus the sacrificed creature's mana value, put it onto the battlefield, then shuffle.
+1: Mill five cards, then put any number of creature cards milled this way into your hand.
−1: Create a 4/4 green Rhino Warrior creature token.

Sporemound

Landfall — Whenever a land you control enters, create a 1/1 green Saproling creature token.

Thallid Germinator

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: Target creature gets +1/+1 until end of turn.

Nemata, Grove Guardian

{2}{G}: Create a 1/1 green Saproling creature token.
Sacrifice a Saproling: Saproling creatures get +1/+1 until end of turn.

Magus of the Order

{G}, {T}, Sacrifice this creature and another green creature: Search your library for a green creature card, put it onto the battlefield, then shuffle.

Fungus Frolic

Create two 1/1 green Saproling creature tokens. (Then exile this card. You may cast the creature later from exile.)

Brightcap Badger

Each Fungus and Saproling you control has "{T}: Add {G}."
At the beginning of your end step, create a 1/1 green Saproling creature token.

Brightcap Badger // Fungus Frolic

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.

Golgari Germination

Whenever a nontoken creature you control dies, create a 1/1 green Saproling creature token.

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.

Thallid Shell-Dweller

Defender
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.

Saproling Symbiosis

You may cast this spell as though it had flash if you pay {2} more to cast it. (You may cast it any time you could cast an instant.)
Create a 1/1 green Saproling creature token for each creature you control.

Eldritch Evolution

As an additional cost to cast this spell, sacrifice a creature.
Search your library for a creature card with mana value X or less, where X is 2 plus the sacrificed creature's mana value. Put that card onto the battlefield, then shuffle. Exile Eldritch Evolution.

Yavimaya Sapherd

When this creature enters, create a 1/1 green Saproling creature token.

Deathbloom Thallid

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

Thallid Omnivore

{1}, Sacrifice another creature: This creature gets +2/+2 until end of turn. If a Saproling was sacrificed this way, you gain 2 life.

Necrogenesis

{2}: Exile target creature card from a graveyard. Create a 1/1 green Saproling creature token.

Slimefoot, the Stowaway

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

Tukatongue Thallid

Sporesower Thallid

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

Fungal Plots

{1}{G}, Exile a creature card from your graveyard: Create a 1/1 green Saproling creature token.
Sacrifice two Saprolings: You gain 2 life and draw a card.

Nemata, Primeval Warden

Reach
If a creature an opponent controls would die, exile it instead. When you do, create a 1/1 green Saproling creature token.
{G}, Sacrifice a Saproling: Nemata gets +2/+2 until end of turn.
{1}{B}, Sacrifice two Saprolings: Draw a card.

Thallid Soothsayer

Sporecrown Thallid

Each other creature you control that's a Fungus or Saproling gets +1/+1.

Undercellar Myconid

Whenever this creature enters or dies, create a 1/1 green Saproling creature token.
{T}: Add one mana of any color.

Infested Thrinax

Flash
When this creature enters, until end of turn, whenever a nontoken creature you control dies, create a number of 1/1 green Saproling creature tokens equal to that creature's power.

Sporoloth Ancient

At the beginning of your upkeep, put a spore counter on this creature.
Creatures you control have "Remove two spore counters from this creature: Create a 1/1 green Saproling creature token."