Omnath, Locus of Mana

You don't lose unspent green mana as steps and phases end.
Omnath, Locus of Mana gets +1/+1 for each unspent green mana you have.

Ainok Guide

When Ainok Guide enters, choose one —
• Put a +1/+1 counter on Ainok Guide.
• Search your library for a basic land card, reveal it, then shuffle and put that card on top.

Spike Drone

Spike Drone enters with a +1/+1 counter on it.
{2}, Remove a +1/+1 counter from Spike Drone: Put a +1/+1 counter on target creature.

Lifecrafter's Gift

Put a +1/+1 counter on target creature, then put a +1/+1 counter on each creature you control with a +1/+1 counter on it.

Forgotten Ancient

Whenever a player casts a spell, you may put a +1/+1 counter on Forgotten Ancient.
At the beginning of your upkeep, you may move any number of +1/+1 counters from Forgotten Ancient onto other creatures.

Leyline of Abundance

If Leyline of Abundance is in your opening hand, you may begin the game with it on the battlefield.
Whenever you tap a creature for mana, add an additional {G}.
{6}{G}{G}: Put a +1/+1 counter on each creature you control.

Rishkar's Expertise

Draw cards equal to the greatest power among creatures you control.
You may cast a spell with mana value 5 or less from your hand without paying its mana cost.

Durable Handicraft

Whenever a creature you control enters, you may pay {1}. If you do, put a +1/+1 counter on that creature.
{5}{G}, Sacrifice Durable Handicraft: Put a +1/+1 counter on each creature you control.

Spike Soldier

Spike Soldier enters with three +1/+1 counters on it.
{2}, Remove a +1/+1 counter from Spike Soldier: Put a +1/+1 counter on target creature.
Remove a +1/+1 counter from Spike Soldier: Spike Soldier gets +2/+2 until end of turn.

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.

Mowu, Loyal Companion

Vigilance, trample
If one or more +1/+1 counters would be put on Mowu, Loyal Companion, that many plus one +1/+1 counters are put on it instead.

Avatar of the Resolute

Reach, trample
Avatar of the Resolute enters with a +1/+1 counter on it for each other creature you control with a +1/+1 counter on it.

Bramblewood Paragon

Each other Warrior creature you control enters with an additional +1/+1 counter on it.
Each creature you control with a +1/+1 counter on it has trample.

Hangarback Walker

Hangarback Walker enters with X +1/+1 counters on it.
When Hangarback Walker dies, create a 1/1 colorless Thopter artifact creature token with flying for each +1/+1 counter on Hangarback Walker.
{1}, {T}: Put a +1/+1 counter on Hangarback Walker.

Rishkar, Peema Renegade

When Rishkar, Peema Renegade enters, put a +1/+1 counter on each of up to two target creatures.
Each creature you control with a counter on it has "{T}: Add {G}."

Courage in Crisis

Put a +1/+1 counter on target creature, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Inspiring Call

Draw a card for each creature you control with a +1/+1 counter on it. Those creatures gain indestructible until end of turn. (Damage and effects that say "destroy" don't destroy them.)

Spike Weaver

Spike Weaver enters with three +1/+1 counters on it.
{2}, Remove a +1/+1 counter from Spike Weaver: Put a +1/+1 counter on target creature.
{1}, Remove a +1/+1 counter from Spike Weaver: Prevent all combat damage that would be dealt this turn.

Crowned Ceratok

Trample
Each creature you control with a +1/+1 counter on it has trample.

Incubation Druid

{T}: Add one mana of any type that a land you control could produce. If Incubation Druid has a +1/+1 counter on it, add three mana of that type instead.
{3}{G}{G}: Adapt 3. (If this creature has no +1/+1 counters on it, put three +1/+1 counters on it.)

Ivy Lane Denizen

Whenever another green creature you control enters, put a +1/+1 counter on target creature.

Autumn's Veil

Spells you control can't be countered by blue or black spells this turn, and creatures you control can't be the targets of blue or black spells this turn.

Woodland Champion

Whenever one or more tokens you control enter, put that many +1/+1 counters on Woodland Champion.

Experiment One

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.)
Remove two +1/+1 counters from Experiment One: Regenerate Experiment One. (The next time this creature would be destroyed, instead tap it, remove it from combat, and heal all damage on it.)

Primeval Bounty

Whenever you cast a creature spell, create a 3/3 green Beast creature token.
Whenever you cast a noncreature spell, put three +1/+1 counters on target creature you control.
Landfall — Whenever a land you control enters, you gain 3 life.

Nature's Spiral

Return target permanent card from your graveyard to your hand.

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.

Song of Freyalise

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — Until your next turn, creatures you control gain "{T}: Add one mana of any color."
III — Put a +1/+1 counter on each creature you control. Those creatures gain vigilance, trample, and indestructible until end of turn.

Biogenic Upgrade

Distribute three +1/+1 counters among one, two, or three target creatures, then double the number of +1/+1 counters on each of those creatures.

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.

Armorcraft Judge

When Armorcraft Judge enters, draw a card for each creature you control with a +1/+1 counter on it.

Bow of Nylea

Attacking creatures you control have deathtouch.
{1}{G}, {T}: Choose one —
• Put a +1/+1 counter on target creature.
• Bow of Nylea deals 2 damage to target creature with flying.
• You gain 3 life.
• Put up to four target cards from your graveyard on the bottom of your library in any order.

Hungering Hydra

Hungering Hydra enters with X +1/+1 counters on it.
Hungering Hydra can't be blocked by more than one creature.
Whenever Hungering Hydra is dealt damage, put that many +1/+1 counters on it. (It must survive the damage to get the counters.)

Spike Tiller

Spike Tiller enters with three +1/+1 counters on it.
{2}, Remove a +1/+1 counter from Spike Tiller: Put a +1/+1 counter on target creature.
{2}, Remove a +1/+1 counter from Spike Tiller: Target land becomes a 2/2 creature that's still a land. Put a +1/+1 counter on it.

Helix Pinnacle

Shroud (This enchantment can't be the target of spells or abilities.)
{X}: Put X tower counters on Helix Pinnacle.
At the beginning of your upkeep, if there are 100 or more tower counters on Helix Pinnacle, you win the game.

Forest

Pelt Collector

Whenever another creature you control enters or dies, if that creature's power is greater than Pelt Collector's, put a +1/+1 counter on Pelt Collector.
As long as Pelt Collector has three or more +1/+1 counters on it, it has trample.

Spike Colony

Spike Colony enters with four +1/+1 counters on it.
{2}, Remove a +1/+1 counter from Spike Colony: Put a +1/+1 counter on target creature.

Primeval Protector

This spell costs {1} less to cast for each creature your opponents control.
When Primeval Protector enters, put a +1/+1 counter on each other creature you control.

Renata, Called to the Hunt

Renata's power is equal to your devotion to green. (Each {G} in the mana costs of permanents you control counts toward your devotion to green.)
Each other creature you control enters with an additional +1/+1 counter on it.

The Great Henge

This spell costs {X} less to cast, where X is the greatest power among creatures you control.
{T}: Add {G}{G}. You gain 2 life.
Whenever a nontoken creature you control enters, put a +1/+1 counter on it and draw a card.

Obsessive Skinner

When Obsessive Skinner enters, put a +1/+1 counter on target creature.
Delirium — At the beginning of each opponent's upkeep, if there are four or more card types among cards in your graveyard, put a +1/+1 counter on target creature.

Path of Discovery

Whenever a creature you control enters, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on the creature, then put the card back or put it into your graveyard.)

Strength of the Tajuru

Multikicker {1} (You may pay an additional {1} any number of times as you cast this spell.)
Choose target creature, then choose another target creature for each time this spell was kicked. Put X +1/+1 counters on each of them.

Ulvenwald Tracker

{1}{G}, {T}: Target creature you control fights another target creature.

Vivien, Champion of the Wilds

You may cast creature spells as though they had flash.
+1: Until your next turn, up to one target creature gains vigilance and reach.
−2: Look at the top three cards of your library. Exile one face down and put the rest on the bottom of your library in any order. For as long as it remains exiled, you may cast it if it's a creature spell.

Walking Ballista

Walking Ballista enters with X +1/+1 counters on it.
{4}: Put a +1/+1 counter on Walking Ballista.
Remove a +1/+1 counter from Walking Ballista: It deals 1 damage to any target.

Solidarity of Heroes

Strive — This spell costs {1}{G} more to cast for each target beyond the first.
Choose any number of target creatures. Double the number of +1/+1 counters on each of them.

Gyre Sage

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.)
{T}: Add {G} for each +1/+1 counter on Gyre Sage.

Bane of Progress

When Bane of Progress enters, destroy all artifacts and enchantments. Put a +1/+1 counter on Bane of Progress for each permanent destroyed this way.

Spike Feeder

Spike Feeder enters with two +1/+1 counters on it.
{2}, Remove a +1/+1 counter from Spike Feeder: Put a +1/+1 counter on target creature.
Remove a +1/+1 counter from Spike Feeder: You gain 2 life.

Surestrike Trident

Equipped creature has first strike and "{T}, Unattach Surestrike Trident: This creature deals damage equal to its power to target player or planeswalker."
Equip {4} ({4}: Attach to target creature you control. Equip only as a sorcery. This card enters unattached and stays on the battlefield if the creature leaves.)

Cultivator of Blades

Fabricate 2 (When this creature enters, put two +1/+1 counters on it or create two 1/1 colorless Servo artifact creature tokens.)
Whenever Cultivator of Blades attacks, you may have other attacking creatures get +X/+X until end of turn, where X is Cultivator of Blades's power.

Managorger Hydra

Trample
Whenever a player casts a spell, put a +1/+1 counter on Managorger Hydra.

Animation Module

Whenever one or more +1/+1 counters are put on a permanent you control, you may pay {1}. If you do, create a 1/1 colorless Servo artifact creature token.
{3}, {T}: Choose a counter on target permanent or player. Give that permanent or player another counter of that kind.

Marwyn, the Nurturer

Whenever another Elf you control enters, put a +1/+1 counter on Marwyn, the Nurturer.
{T}: Add an amount of {G} equal to Marwyn's power.

Jiang Yanggu, Wildcrafter

Each creature you control with a +1/+1 counter on it has "{T}: Add one mana of any color."
−1: Put a +1/+1 counter on target creature.

Harmonize

Implement of Ferocity

{G}, Sacrifice Implement of Ferocity: Put a +1/+1 counter on target creature. Activate only as a sorcery.
When Implement of Ferocity is put into a graveyard from the battlefield, draw a card.

Hardened Scales

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

Death's Presence

Whenever a creature you control dies, put X +1/+1 counters on target creature you control, where X is the power of the creature that died.

Nature's Claim

Destroy target artifact or enchantment. Its controller gains 4 life.

Spike Breeder

Spike Breeder enters with three +1/+1 counters on it.
{2}, Remove a +1/+1 counter from Spike Breeder: Put a +1/+1 counter on target creature.
{2}, Remove a +1/+1 counter from Spike Breeder: Create a 1/1 green Spike creature token.

Steelbane Hydra

Steelbane Hydra enters with X +1/+1 counters on it.
{2}{G}, Remove a +1/+1 counter from Steelbane Hydra: Destroy target artifact or enchantment.

Servant of the Scale

Servant of the Scale enters with a +1/+1 counter on it.
When Servant of the Scale dies, put X +1/+1 counters on target creature you control, where X is the number of +1/+1 counters on Servant of the Scale.