The Weatherseed Treaty

Read ahead (Choose a chapter and start with that many lore counters. Add one after your draw step. Skipped chapters don't trigger. Sacrifice after III.)
I — Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
II — Create a 1/1 green Saproling creature token.
III — Domain — Target creature you control gets +X/+X and gains trample until end of turn, where X is the number of basic land types among lands you control.

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.

Savage 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.
Sacrifice a Saproling: Regenerate target Fungus.

Saproling Migration

Kicker {4} (You may pay an additional {4} as you cast this spell.)
Create two 1/1 green Saproling creature tokens. If this spell was kicked, create four of those tokens instead.

Naturalize

Druid's Deliverance

Prevent all combat damage that would be dealt to you this turn. Populate. (Create a token that's a copy of a creature token you control.)

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.

Mold Folk

Lifelink
Mold Harvest — {1}, Sacrifice another creature or an artifact: Put a +1/+1 counter on this creature.

Rot Shambler

Whenever another creature you control dies, put a +1/+1 counter on this creature.

Sporemound

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

Scatter the Seeds

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Create three 1/1 green Saproling creature tokens.

Moldervine Reclamation

Whenever a creature you control dies, you gain 1 life and draw a card.

Binding the Old Gods

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Destroy target nonland permanent an opponent controls.
II — Search your library for a Forest card, put it onto the battlefield tapped, then shuffle.
III — Creatures you control gain deathtouch until end of turn.

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.

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."

Unnatural Restoration

Return target permanent card from your graveyard to your hand. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Rhizome Lurcher

Undergrowth — This creature enters with a number of +1/+1 counters on it equal to the number of creature cards in your graveyard.

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 Charm

Choose one —
• All creatures get -1/-1 until end of turn.
• Destroy target enchantment.
• Regenerate each creature you control.

Tukatongue Thallid

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

Fungal Infection

Target creature gets -1/-1 until end of turn. Create a 1/1 green Saproling creature token.

Trudge Garden

Whenever you gain life, you may pay {2}. If you do, create a 4/4 green Fungus Beast creature token with trample.

Sprout Swarm

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Buyback {3} (You may pay an additional {3} as you cast this spell. If you do, put this card into your hand as it resolves.)
Create a 1/1 green Saproling creature token.

Sprout

Create a 1/1 green Saproling creature token.

Death Mutation

Destroy target nonblack creature. It can't be regenerated. Create X 1/1 green Saproling creature tokens, where X is that creature's mana value.

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.

Gruesome Fate

Each opponent loses 1 life for each creature you control.

Forest

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Fungal Rebirth

Return target permanent card from your graveyard to your hand. If a creature died this turn, create two 1/1 green Saproling creature tokens.

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.

Saproling Cluster

{1}, Discard a card: Create a 1/1 green Saproling creature token. Any player may activate this ability.

Drown in Ichor

Target creature gets -4/-4 until end of turn. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Golgari Cluestone

{T}: Add {B} or {G}.
{B}{G}, {T}, Sacrifice this artifact: Draw a card.

Sarpadian Empires, Vol. VII

As this artifact enters, choose white Citizen, blue Camarid, black Thrull, red Goblin, or green Saproling.
{3}, {T}: Create a 1/1 creature token of the chosen color and type.

Haunted Mire

({T}: Add {B} or {G}.)
This land enters tapped.

Deathspore 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.
Sacrifice a Saproling: Target creature gets -1/-1 until end of turn.

Cankerbloom

{1}, Sacrifice this creature: Choose one —
• Destroy target artifact.
• Destroy target enchantment.
• Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Sporecrown Thallid

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

Necrogenesis

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

Corpsejack Menace

If one or more +1/+1 counters would be put on a creature you control, twice that many +1/+1 counters are put on it instead.

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.

Pick Your Poison

Choose one —
• Each opponent sacrifices an artifact of their choice.
• Each opponent sacrifices an enchantment of their choice.
• Each opponent sacrifices a creature with flying of their choice.

Druidic Satchel

{2}, {T}: Reveal the top card of your library. If it's a creature card, create a 1/1 green Saproling creature token. If it's a land card, put that card onto the battlefield under your control. If it's a noncreature, nonland card, you gain 2 life.

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.

Yavimaya Sapherd

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

Utopia Mycon

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: Add one mana of any color.

Molderhulk

Undergrowth — This spell costs {1} less to cast for each creature card in your graveyard.
When this creature enters, return target land card from your graveyard to the battlefield.

Vitaspore 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.
Sacrifice a Saproling: Target creature gains haste until end of turn.

The Mycotyrant

Trample
The Mycotyrant's power and toughness are each equal to the number of creatures you control that are Fungi and/or Saprolings.
At the beginning of your end step, create X 1/1 black Fungus creature tokens with "This token can't block," where X is the number of times you descended this turn. (You descend each time a permanent card is put into your graveyard from anywhere.)

Roaming Throne

Ward {2}
As this creature enters, choose a creature type.
This creature is the chosen type in addition to its other types.
If a triggered ability of another creature you control of the chosen type triggers, it triggers an additional time.

Flash Foliage

Cast this spell only during combat after blockers are declared.
Create a 1/1 green Saproling creature token that's blocking target creature attacking you.
Draw a card.

Full Flowering

Populate X times. (To populate, create a token that's a copy of a creature token you control. Do this X times.)

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Deathbloom Thallid

Grow from the Ashes

Kicker {2} (You may pay an additional {2} as you cast this spell.)
Search your library for a basic land card, put it onto the battlefield, then shuffle. If this spell was kicked, instead search your library for two basic land cards, put them onto the battlefield, then shuffle.

Life and Limb

All Forests and all Saprolings are 1/1 green Saproling creatures and Forest lands in addition to their other types. (They're affected by summoning sickness.)

Fungal Sprouting

Create X 1/1 green Saproling creature tokens, where X is the greatest power among creatures you control.

Myconid Spore Tender

Infesting Spores — When this creature enters, destroy up to one target artifact or enchantment.

Thriving Grove

This land enters tapped. As it enters, choose a color other than green.
{T}: Add {G} or one mana of the chosen color.

Undercellar Myconid

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

Swamp

Golgari Germination

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

Spore Swarm

Create three 1/1 green Saproling creature tokens.

Golgari Locket

{T}: Add {B} or {G}.
{B/G}{B/G}{B/G}{B/G}, {T}, Sacrifice this artifact: Draw two cards.

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.

Talisman of Resilience

{T}: Add {C}.
{T}: Add {B} or {G}. This artifact deals 1 damage to you.

Fists of Ironwood

Enchant creature
When this Aura enters, create two 1/1 green Saproling creature tokens.
Enchanted creature has trample.