Overcome

Creatures you control get +2/+2 and gain trample until end of turn. (Each of those creatures can deal excess combat damage to the player or planeswalker it's attacking.)

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.

Saurian Symbiote

Reach (This creature can block creatures with flying.)
When Saurian Symbiote enters, choose one —
• Put a +1/+1 counter on Saurian Symbiote.
• Create a 1/1 green Saproling creature token.

Forest

Thriving Grove

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

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.

Slimy Piper

Whenever Slimy Piper attacks, it gets +1/+1 until end of turn. If you control four or more creatures, it gets +2/+2 and gains indestructible until end of turn instead. (Damage and effects that say "destroy" don't destroy it.)

Shroofus Sproutsire

Trample
Whenever a Saproling you control deals combat damage to a player, create that many 1/1 green Saproling creature tokens.

Sporecrown Thallid

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

For the Family

Target creature gets +2/+2 until end of turn. If you control four or more creatures, that creature gets +4/+4 until end of turn instead.

Undercellar Myconid

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

Band Together

Up to two target creatures you control each deal damage equal to their power to another target creature.

Spore Swarm

Create three 1/1 green Saproling creature tokens.

Verdeloth the Ancient

Kicker {X} (You may pay an additional {X} as you cast this spell.)
Saproling creatures and other Treefolk creatures get +1/+1.
When Verdeloth the Ancient enters, if it was kicked, create X 1/1 green Saproling creature tokens.