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 Sporogenesis leaves the battlefield, remove all fungus counters from all creatures.

Anointed Procession

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

Fecundity

Whenever a creature dies, that creature's controller may draw a card.

Saltcrusted Steppe

{T}: Add {C}.
{1}, {T}: Put a storage counter on Saltcrusted Steppe.
{1}, Remove X storage counters from Saltcrusted Steppe: Add X mana in any combination of {G} and/or {W}.

Camaraderie

You gain X life and draw X cards, where X is the number of creatures you control. Creatures you control get +1/+1 until end of turn.

Saproling Symbiosis

You may cast Saproling Symbiosis 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.

Utopia Mycon

At the beginning of your upkeep, put a spore counter on Utopia Mycon.
Remove three spore counters from Utopia Mycon: Create a 1/1 green Saproling creature token.
Sacrifice a Saproling: Add one mana of any color.

Contagion Clasp

When Contagion Clasp enters, put a -1/-1 counter on target creature.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Divine Visitation

If one or more creature tokens would be created under your control, that many 4/4 white Angel creature tokens with flying and vigilance are created instead.

Ghave, Guru of Spores

Ghave, Guru of Spores 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.

Deathreap Ritual

Morbid — At the beginning of each end step, if a creature died this turn, you may draw a card.

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.

Unbreakable Formation

Creatures you control gain indestructible until end of turn.
Addendum — If you cast this spell during your main phase, put a +1/+1 counter on each of those creatures and they gain vigilance until end of turn.

Swamp

Aura Mutation

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

Terramorphic Expanse

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Sporemound

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

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Seaside Citadel

Seaside Citadel enters tapped.
{T}: Add {G}, {W}, or {U}.

Elvish Farmer

At the beginning of your upkeep, put a spore counter on Elvish Farmer.
Remove three spore counters from Elvish Farmer: Create a 1/1 green Saproling creature token.
Sacrifice a Saproling: You gain 2 life.

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.

Mentor of the Meek

Whenever another creature you control with power 2 or less enters, you may pay {1}. If you do, draw a card.

Island

Calciform Pools

{T}: Add {C}.
{1}, {T}: Put a storage counter on Calciform Pools.
{1}, Remove X storage counters from Calciform Pools: Add X mana in any combination of {W} and/or {U}.

Tezzeret's Gambit

({U/P} can be paid with either {U} or 2 life.)
Draw two cards, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Pir, Imaginative Rascal

Partner with Toothy, Imaginary Friend (When this creature enters, target player may put Toothy into their hand from their library, then shuffle.)
If one or more counters would be put on a permanent your team controls, that many plus one of each of those kinds of counters are put on that permanent instead.

Novijen, Heart of Progress

{T}: Add {C}.
{G}{U}, {T}: Put a +1/+1 counter on each creature that entered this turn.

Moldervine Reclamation

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

Fuel for the Cause

Counter target spell, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Mythos of Nethroi

Destroy target nonland permanent if it's a creature or if {G}{W} was spent to cast this spell.

Dictate of Erebos

Flash
Whenever a creature you control dies, each opponent sacrifices a creature of their choice.

Rot Shambler

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

Evolving Wilds

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Vampiric Rites

{1}{B}, Sacrifice a creature: You gain 1 life and draw a card.

Sandsteppe Citadel

Sandsteppe Citadel enters tapped.
{T}: Add {W}, {B}, or {G}.

Astral Cornucopia

Astral Cornucopia enters with X charge counters on it.
{T}: Choose a color. Add one mana of that color for each charge counter on Astral Cornucopia.

Fathom Mage

Evolve (Whenever a creature you control enters, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)
Whenever a +1/+1 counter is put on Fathom Mage, you may draw a card.

Itlimoc, Cradle of the Sun

(Transforms from Growing Rites of Itlimoc.)
{T}: Add {G}.
{T}: Add {G} for each creature you control.

Growing Rites of Itlimoc

When Growing Rites of Itlimoc enters, look at the top four cards of your library. You may reveal a creature card from among them and put it into your hand. Put the rest on the bottom of your library in any order.
At the beginning of your end step, if you control four or more creatures, transform Growing Rites of Itlimoc.

Growing Rites of Itlimoc // Itlimoc, Cradle of the Sun

Savage Thallid

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

Sporoloth Ancient

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

Mycologist

At the beginning of your upkeep, put a spore counter on Mycologist.
Remove three spore counters from Mycologist: Create a 1/1 green Saproling creature token.
Sacrifice a Saproling: You gain 2 life.

Poison-Tip Archer

Reach (This creature can block creatures with flying.)
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Whenever another creature dies, each opponent loses 1 life.

Forest

Shamanic Revelation

Draw a card for each creature you control.
Ferocious — You gain 4 life for each creature you control with power 4 or greater.

Rampant Growth

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

Thallid Soothsayer

Paradox Haze

Enchant player
At the beginning of enchanted player's first upkeep each turn, that player gets an additional upkeep step after this step.

Willing

Creatures you control gain deathtouch and lifelink until end of turn.
Fuse (You may cast one or both halves of this card from your hand.)

Ready

Creatures you control gain indestructible until end of turn. Untap each creature you control.
Fuse (You may cast one or both halves of this card from your hand.)

Ready // Willing

Plaguemaw Beast

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

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Smothering Abomination

Devoid (This card has no color.)
Flying
At the beginning of your upkeep, sacrifice a creature.
Whenever you sacrifice a creature, draw a card.

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

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.

Teferi's Protection

Until your next turn, your life total can't change and you gain protection from everything. All permanents you control phase out. (While they're phased out, they're treated as though they don't exist. They phase in before you untap during your untap step.)
Exile Teferi's Protection.

Opal Palace

{T}: Add {C}.
{1}, {T}: Add one mana of any color in your commander's color identity. If you spend this mana to cast your commander, it enters with a number of additional +1/+1 counters on it equal to the number of times it's been cast from the command zone this game.

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."

Second Harvest

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

Aura Shards

Whenever a creature you control enters, you may destroy target artifact or enchantment.

Vivid Creek

Vivid Creek enters tapped with two charge counters on it.
{T}: Add {U}.
{T}, Remove a charge counter from Vivid Creek: Add one mana of any color.

Vivid Meadow

Vivid Meadow enters tapped with two charge counters on it.
{T}: Add {W}.
{T}, Remove a charge counter from Vivid Meadow: Add one mana of any color.

Negate

Vivid Marsh

Vivid Marsh enters tapped with two charge counters on it.
{T}: Add {B}.
{T}, Remove a charge counter from Vivid Marsh: Add one mana of any color.

Zagoth Triome

({T}: Add {B}, {G}, or {U}.)
Zagoth Triome enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Reliquary Tower

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

Selesnya Signet

Vorel of the Hull Clade

{G}{U}, {T}: Double the number of each kind of counter on target artifact, creature, or land.

Cryptolith Rite

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

Crystalline Crawler

Converge — Crystalline Crawler enters with a +1/+1 counter on it for each color of mana spent to cast it.
Remove a +1/+1 counter from Crystalline Crawler: Add one mana of any color.
{T}: Put a +1/+1 counter on Crystalline Crawler.

Necrogenesis

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

Chromatic Lantern

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

Tragic Slip

Target creature gets -1/-1 until end of turn.
Morbid — That creature gets -13/-13 until end of turn instead if a creature died this turn.

Azorius Signet

Sphinx of the Second Sun

Flying
At the beginning of each of your postcombat main phases, there is an additional beginning phase after this phase. (The beginning phase includes the untap, upkeep, and draw steps.)

Wrap in Vigor

Thorn Thallid

At the beginning of your upkeep, put a spore counter on Thorn Thallid.
Remove three spore counters from Thorn Thallid: It deals 1 damage to any target.

Lifecrafter's Bestiary

At the beginning of your upkeep, scry 1.
Whenever you cast a creature spell, you may pay {G}. If you do, draw a card.

Distant Melody

Choose a creature type. Draw a card for each permanent you control of that type.

Thallid Devourer

At the beginning of your upkeep, put a spore counter on Thallid Devourer.
Remove three spore counters from Thallid Devourer: Create a 1/1 green Saproling creature token.
Sacrifice a Saproling: Thallid Devourer gets +1/+2 until end of turn.

Kodama's Reach

Zulaport Cutthroat

Whenever Zulaport Cutthroat or another creature you control dies, each opponent loses 1 life and you gain 1 life.

Simic Signet

Harrow

As an additional cost to cast this spell, sacrifice a land.
Search your library for up to two basic land cards, put them onto the battlefield, then shuffle.

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.

Sporesower Thallid

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

Seed Spark

Destroy target artifact or enchantment. If {G} was spent to cast this spell, create two 1/1 green Saproling creature tokens.

Golgari Signet

Spore Flower

At the beginning of your upkeep, put a spore counter on Spore Flower.
Remove three spore counters from Spore Flower: Prevent all combat damage that would be dealt this turn.

Atraxa, Praetors' Voice

Flying, vigilance, deathtouch, lifelink
At the beginning of your end step, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Deathsprout

Destroy target creature. Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Command Tower

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

Adrix and Nev, Twincasters

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
If one or more tokens would be created under your control, twice that many of those tokens are created instead.

Plains

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.)

Explosive Vegetation

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

Arcane Signet

Sporecrown Thallid

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

Gavony Township

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

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.

Contagion Engine

When Contagion Engine enters, put a -1/-1 counter on each creature target player controls.
{4}, {T}: Proliferate twice. (Choose any number of permanents and/or players, then give each another counter of each kind already there. Then do it again.)

Mycoloth

Devour 2 (As this enters, you may sacrifice any number of creatures. This creature 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 Mycoloth.

Fellwar Stone

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Farseek

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

Vorinclex, Monstrous Raider

Trample, haste
If you would put one or more counters on a permanent or player, put twice that many of each of those kinds of counters on that permanent or player instead.
If an opponent would put one or more counters on a permanent or player, they put half that many of each of those kinds of counters on that permanent or player instead, rounded down.

Inexorable Tide

Whenever you cast a spell, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)