Night Soil

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

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, Primeval Warden gets +2/+2 until end of turn.
{1}{B}, Sacrifice two Saprolings: Draw a card.

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.

Goblin Bombardment

Sacrifice a creature: Goblin Bombardment deals 1 damage to any target.

Korozda Guildmage

{1}{B}{G}: Target creature gets +1/+1 and gains intimidate until end of turn. (It can't be blocked except by artifact creatures and/or creatures that share a color with it.)
{2}{B}{G}, Sacrifice a nontoken creature: Create X 1/1 green Saproling creature tokens, where X is the sacrificed creature's toughness.

Altar's Reap

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards.

Spontaneous Generation

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

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.

Etali, Primal Sickness

Trample, indestructible
Whenever Etali, Primal Sickness deals combat damage to a player, they get that many poison counters. (A player with ten or more poison counters loses the game.)

Etali, Primal Conqueror

Trample
When Etali, Primal Conqueror enters, each player exiles cards from the top of their library until they exile a nonland card. You may cast any number of spells from among the nonland cards exiled this way without paying their mana costs.
{9}{G/P}: Transform Etali. Activate only as a sorcery.

Etali, Primal Conqueror // Etali, Primal Sickness

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.

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.

Saproling Cluster

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

Fungal Infection

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

Sarpadian Empires, Vol. VII

As Sarpadian Empires, Vol. VII 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.

Spore Swarm

Create three 1/1 green Saproling creature tokens.

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.

Golgari Germination

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

Artifact Mutation

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

Necrogenesis

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

Blood for Bones

As an additional cost to cast this spell, sacrifice a creature.
Return a creature card from your graveyard to the battlefield, then return another creature card from your graveyard to your hand.

Sprout

Create a 1/1 green Saproling creature token.

Attrition

{B}, Sacrifice a creature: Destroy target nonblack creature.

Flayer of the Hatebound

Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)
Whenever Flayer of the Hatebound or another creature enters from your graveyard, that creature deals damage equal to its power to any target.

Slimefoot and Squee

Whenever Slimefoot and Squee enters or attacks, create a 1/1 green Saproling creature token.
{1}{B}{R}{G}, Sacrifice a Saproling: Return Slimefoot and Squee and up to one other target creature card from your graveyard to the battlefield. Activate only as a sorcery.