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.

Rampant Growth

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

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.

Mirari's Wake

Creatures you control get +1/+1.
Whenever you tap a land for mana, add one mana of any type that land produced.

Pallid Mycoderm

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: Each creature you control that's a Fungus or a Saproling gets +1/+1 until end of turn.

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.)

Verdant Embrace

Enchant creature
Enchanted creature gets +3/+3 and has "At the beginning of each upkeep, 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.

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.

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.

Night Soil

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

Forest

Plains

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.

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.

Collective Blessing

Coat of Arms

Each creature gets +1/+1 for each other creature on the battlefield that shares at least one creature type with it. (For example, if two Goblin Warriors and a Goblin Shaman are on the battlefield, each gets +2/+2.)

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."

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

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.

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

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.

Thriving Moor

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

Sporeweb Weaver

Reach, hexproof from blue
Whenever this creature is dealt damage, you gain 1 life and create a 1/1 green Saproling creature token.

Abundant Growth

Enchant land
When this Aura enters, draw a card.
Enchanted land has "{T}: Add one mana of any color."

Mortuary Mire

This land enters tapped.
When this land enters, you may put target creature card from your graveyard on top of your library.
{T}: Add {B}.

Spore Frog

Sacrifice this creature: Prevent all combat damage that would be dealt this turn.

Vitu-Ghazi, the City-Tree

{T}: Add {C}.
{2}{G}{W}, {T}: Create a 1/1 green Saproling creature token.

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.

Cathars' Crusade

Whenever a creature you control enters, put a +1/+1 counter on each creature you control.

Moldervine Reclamation

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

Temple of the False God

{T}: Add {C}{C}. Activate only if you control five or more lands.

Evolution Sage

Landfall — Whenever a land you control enters, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Seed Spark

Destroy target artifact or enchantment. If {G} was spent to cast this spell, 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.

Gruesome Fate

Each opponent loses 1 life for each creature 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.

Tukatongue Thallid

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

Tranquil Thicket

This land enters tapped.
{T}: Add {G}.
Cycling {G} ({G}, Discard this card: Draw a card.)

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.

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.

Rootborn Defenses

Populate. Creatures you control gain indestructible until end of turn. (To populate, create a token that's a copy of a creature token you control.)

Eerie Ultimatum

Return any number of permanent cards with different names from your graveyard to the battlefield.

Undergrowth Stadium

This land enters tapped unless you have two or more opponents.
{T}: Add {B} or {G}.

Tendershoot Dryad

Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
At the beginning of each upkeep, create a 1/1 green Saproling creature token.
Saprolings you control get +2/+2 as long as you have the city's blessing.

Aura Mutation

Destroy target enchantment. Create X 1/1 green Saproling creature tokens, where X is that enchantment's mana value.

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.

Thelon of Havenwood

Each Fungus creature gets +1/+1 for each spore counter on it.
{B}{G}, Exile a Fungus card from a graveyard: Put a spore counter on each Fungus on the battlefield.

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.

Winding Constrictor

If one or more counters would be put on an artifact or creature you control, that many plus one of each of those kinds of counters are put on that permanent instead.
If you would get one or more counters, you get that many plus one of each of those kinds of counters instead.

The Ozolith

Whenever a creature you control leaves the battlefield, if it had counters on it, put those counters on The Ozolith.
At the beginning of combat on your turn, if The Ozolith has counters on it, you may move all counters from The Ozolith onto target creature.

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.

Eldrazi Monument

Creatures you control get +1/+1 and have flying and indestructible.
At the beginning of your upkeep, sacrifice a creature. If you can't, sacrifice this artifact.

Fungal Sprouting

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

Undercellar Myconid

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

Parallel Lives

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.

Karn's Bastion

{T}: Add {C}.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Sundering Growth

Destroy target artifact or enchantment, then populate. (Create a token that's a copy of a creature token you control.)

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.

Rot Shambler

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

Bojuka Bog

This land enters tapped.
When this land enters, exile target player's graveyard.
{T}: Add {B}.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Mindbender Spores

Defender (This creature can't attack.)
Flying
Whenever this creature blocks a creature, put four fungus counters on that creature. The creature gains "This creature doesn't untap during your untap step if it has a fungus counter on it" and "At the beginning of your upkeep, remove a fungus counter from this creature."

Deathbloom Thallid

Ghave, Guru of Spores

Ghave enters with five +1/+1 counters on it.
{1}, Remove a +1/+1 counter from a creature you control: Create a 1/1 green Saproling creature token.
{1}, Sacrifice a creature: Put a +1/+1 counter on target creature.

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.

Cryptolith Rite

Creatures you control have "{T}: Add one mana of any color."

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.

Morbid Bloom

Exile target creature card from a graveyard, then create X 1/1 green Saproling creature tokens, where X is the exiled card's toughness.

Sporogenesis

At the beginning of your upkeep, you may put a fungus counter on target nontoken creature.
Whenever a creature with a fungus counter on it dies, create a 1/1 green Saproling creature token for each fungus counter on that creature.
When this enchantment leaves the battlefield, remove all fungus counters from all creatures.

Yavimaya Sapherd

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

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.

Sporecrown Thallid

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

Growing Ranks

At the beginning of your upkeep, populate. (Create a token that's a copy of a creature token you control.)

Harvest Season

Search your library for up to X basic land cards, where X is the number of tapped creatures you control, put those cards onto the battlefield tapped, then shuffle.

Intangible Virtue

Creature tokens you control get +1/+1 and have vigilance.

Spontaneous Generation

Create a 1/1 green Saproling creature token for each card in your hand.

Mycologist

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.

Oran-Rief, the Vastwood

This land enters tapped.
{T}: Add {G}.
{T}: Put a +1/+1 counter on each green creature that entered this turn.

Vanquisher's Banner

As this artifact enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
Whenever you cast a creature spell of the chosen type, draw a card.

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.

Mold Adder

Whenever an opponent casts a blue or black spell, you may put a +1/+1 counter on this creature.

Grim Backwoods

{T}: Add {C}.
{2}{B}{G}, {T}, Sacrifice a creature: Draw a card.

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.

Verdant Force

At the beginning of each upkeep, create a 1/1 green Saproling creature token.

Boneyard Mycodrax

Boneyard Mycodrax's power and toughness are each equal to the number of other creature cards in your graveyard.
Scavenge {4}{B} ({4}{B}, Exile this card from your graveyard: Put a number of +1/+1 counters equal to this card's power on target creature. Scavenge only as a sorcery.)

Second Harvest

For each token you control, create a token that's a copy of that permanent.

Explosive Vegetation

Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Spore Swarm

Create three 1/1 green Saproling creature tokens.

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.

Epic Struggle

At the beginning of your upkeep, if you control twenty or more creatures, you win the game.

Doubling Season

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.
If an effect would put one or more counters on a permanent you control, it puts twice that many of those counters on that permanent instead.

Fungal Bloom

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

Gavony Township

{T}: Add {C}.
{2}{G}{W}, {T}: Put a +1/+1 counter on each creature you control.

Mycoloth

Devour 2 (As this creature enters, you may sacrifice any number of creatures. It enters with twice that many +1/+1 counters on it.)
At the beginning of your upkeep, create a 1/1 green Saproling creature token for each +1/+1 counter on this creature.

Psychotrope 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.
{1}, Sacrifice a Saproling: Draw a card.

Sporemound

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

Fungal Behemoth

Fungal Behemoth's power and toughness are each equal to the number of +1/+1 counters on creatures you control.
Suspend X—{X}{G}{G}. X can't be 0. (Rather than cast this card from your hand, you may pay {X}{G}{G} and exile it with X time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost. It has haste.)
Whenever a time counter is removed from this card while it's exiled, you may put a +1/+1 counter on target creature.

Kodama's Reach

Swarm Shambler

This creature enters with a +1/+1 counter on it.
Whenever a creature you control with a +1/+1 counter on it becomes the target of a spell an opponent controls, create a 1/1 green Insect creature token.
{1}, {T}: Put a +1/+1 counter on this creature.

Blightsower Thallid

When this creature transforms into Blightsower Thallid or dies, create a 1/1 green Phyrexian Saproling creature token.

Blightreaper Thallid

{3}{G/P}: Transform this creature. Activate only as a sorcery. ({G/P} can be paid with either {G} or 2 life.)