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.

Aquastrand Spider

Graft 2 (This creature enters the battlefield with two +1/+1 counters on it. Whenever another creature enters the battlefield, you may move a +1/+1 counter from this creature onto it.)
{G}: Target creature with a +1/+1 counter on it gains reach until end of turn. (It can block creatures with flying.)

Hunger of the Howlpack

Put a +1/+1 counter on target creature.
Morbid — Put three +1/+1 counters on that creature instead if a creature died this turn.

Invigorating Surge

Put a +1/+1 counter on target creature you control, then double the number of +1/+1 counters on that creature.

Snake Umbra

Enchant creature
Enchanted creature gets +1/+1 and has "Whenever this creature deals damage to an opponent, you may draw a card."
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Forge of Heroes

{T}: Add {C}.
{T}: Choose target commander that entered the battlefield this turn. Put a +1/+1 counter on it if it's a creature and a loyalty counter on it if it's a planeswalker.

Living Totem

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.)
When Living Totem enters the battlefield, you may put a +1/+1 counter on another target creature.

Fertilid

Fertilid enters the battlefield with two +1/+1 counters on it.
{1}{G}, Remove a +1/+1 counter from Fertilid: Target player searches their library for a basic land card, puts it onto the battlefield tapped, then shuffles.

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 the battlefield 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.

Glowstone Recluse

Mutate {3}{G} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Reach
Whenever this creature mutates, put two +1/+1 counters on it.

Ancient Animus

Put a +1/+1 counter on target creature you control if it's legendary. Then it fights target creature an opponent controls. (Each deals damage equal to its power to the other.)

Strider Harness

Equipped creature gets +1/+1 and has haste.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Stony Strength

Put a +1/+1 counter on target creature you control. Untap that creature.

Obsessive Skinner

When Obsessive Skinner enters the battlefield, 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.

Littjara Glade-Warden

Changeling (This card is every creature type.)
{2}{G}, {T}, Exile a creature card from your graveyard: Put two +1/+1 counters on target creature. Activate only as a sorcery.

Timberland Guide

When Timberland Guide enters the battlefield, put a +1/+1 counter on target creature.

Hydra's Growth

Enchant creature
When Hydra's Growth enters the battlefield, put a +1/+1 counter on enchanted creature.
At the beginning of your upkeep, double the number of +1/+1 counters on enchanted creature.

Drudge Beetle

Scavenge {5}{G} ({5}{G}, 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.)

Evolution Sage

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

Satyr Grovedancer

When Satyr Grovedancer enters the battlefield, put a +1/+1 counter on target creature.

Slurrk, All-Ingesting

Slurrk, All-Ingesting enters the battlefield with five +1/+1 counters on it.
Whenever Slurrk or another creature you control dies, if it had a +1/+1 counter on it, put a +1/+1 counter on each creature you control that has a +1/+1 counter on it.
Partner (You can have two commanders if both have partner.)

Oran-Rief Ooze

When Oran-Rief Ooze enters the battlefield, put a +1/+1 counter on target creature you control.
Whenever Oran-Rief Ooze attacks, put a +1/+1 counter on each attacking creature with a +1/+1 counter on it.

Dauntless Survivor

When Dauntless Survivor enters the battlefield, put a +1/+1 counter on target creature.

Llanowar Tribe

New Horizons

Enchant land
When New Horizons enters the battlefield, put a +1/+1 counter on target creature you control.
Enchanted land has "{T}: Add two mana of any one color."

Dragonscale Boon

Put two +1/+1 counters on target creature and untap it.

Titanic Brawl

This spell costs {1} less to cast if it targets a creature you control with a +1/+1 counter on it.
Target creature you control fights target creature you don't control. (Each deals damage equal to its power to the other.)

Lead by Example

Support 2. (Put a +1/+1 counter on each of up to two target creatures.)

Druid of the Cowl

Forest

Battlegrowth

Simic Initiate

Graft 1 (This creature enters the battlefield with a +1/+1 counter on it. Whenever another creature enters the battlefield, you may move a +1/+1 counter from this creature onto it.)

Alpha Authority

Enchant creature
Enchanted creature has hexproof and can't be blocked by more than one creature.

Forced Adaptation

Enchant creature
At the beginning of your upkeep, put a +1/+1 counter on enchanted creature.

Naturalize

Snakeskin Veil

Put a +1/+1 counter on target creature you control. It gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Fleetfeather Sandals

Equipped creature has flying and haste.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Pridemalkin

When Pridemalkin enters the battlefield, put a +1/+1 counter on target creature you control.
Each creature you control with a +1/+1 counter on it has trample. (They can deal excess combat damage to the player or planeswalker they're attacking.)

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.

Scrounging Bandar

Scrounging Bandar enters the battlefield with two +1/+1 counters on it.
At the beginning of your upkeep, you may move any number of +1/+1 counters from Scrounging Bandar onto another target creature.

Arbor Armament

Put a +1/+1 counter on target creature. That creature gains reach until end of turn.

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.

Ordeal of Nylea

Enchant creature
Whenever enchanted creature attacks, put a +1/+1 counter on it. Then if it has three or more +1/+1 counters on it, sacrifice Ordeal of Nylea.
When you sacrifice Ordeal of Nylea, search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

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.

Might Beyond Reason

Put two +1/+1 counters on target creature.
Delirium — Put three +1/+1 counters on that creature instead if there are four or more card types among cards in your graveyard.

Crash of Rhino Beetles

Trample
Crash of Rhino Beetles gets +10/+10 as long as you control ten or more lands.

Curse of Predation

Enchant player
Whenever a creature attacks enchanted player, put a +1/+1 counter on it.

Leafkin Druid

{T}: Add {G}. If you control four or more creatures, add {G}{G} instead.

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.

Return to Nature

Choose one —
• Destroy target artifact.
• Destroy target enchantment.
• Exile target card from a graveyard.

Retreat to Kazandu

Landfall — Whenever a land enters the battlefield under your control, choose one —
• Put a +1/+1 counter on target creature.
• You gain 2 life.

Saddleback Lagac

When Saddleback Lagac enters the battlefield, support 2. (Put a +1/+1 counter on each of up to two other target creatures.)

Weapon Rack

Weapon Rack enters the battlefield with three +1/+1 counters on it.
{T}: Move a +1/+1 counter from Weapon Rack onto target creature. Activate only as a sorcery.

Iron Bully

Menace (This creature can't be blocked except by two or more creatures.)
When Iron Bully enters the battlefield, put a +1/+1 counter on target creature.

Bond Beetle

When Bond Beetle enters the battlefield, put a +1/+1 counter on target creature.

Ferocity

Enchant creature
Whenever enchanted creature blocks or becomes blocked, you may put a +1/+1 counter on it.

Ironshell Beetle

When Ironshell Beetle enters the battlefield, put a +1/+1 counter on target creature.

Nature's Panoply

Strive — This spell costs {2}{G} more to cast for each target beyond the first.
Choose any number of target creatures. Put a +1/+1 counter on each of them.

Iridescent Hornbeetle

At the beginning of your end step, create a 1/1 green Insect creature token for each +1/+1 counter you've put on creatures under your control this turn.

Kujar Seedsculptor

When Kujar Seedsculptor enters the battlefield, put a +1/+1 counter on target creature you control.

Sparring Construct

When Sparring Construct dies, put a +1/+1 counter on target creature you control.

Pollenbright Druid

When Pollenbright Druid enters the battlefield, choose one —
• Put a +1/+1 counter on target creature.
• Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

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.

Armory of Iroas

Whenever equipped creature attacks, put a +1/+1 counter on it.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Longshot Squad

Outlast {1}{G} ({1}{G}, {T}: Put a +1/+1 counter on this creature. Outlast only as a sorcery.)
Each creature you control with a +1/+1 counter on it has reach. (A creature with reach can block creatures with flying.)

Ring of Kalonia

Equipped creature has trample. (It can deal excess combat damage to the player or planeswalker it's attacking.)
At the beginning of your upkeep, put a +1/+1 counter on equipped creature if it's green.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

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.

Sporeback Troll

Graft 2 (This creature enters the battlefield with two +1/+1 counters on it. Whenever another creature enters the battlefield, you may move a +1/+1 counter from this creature onto it.)
{1}{G}: Regenerate target creature with a +1/+1 counter on it.

Ranger's Guile

Target creature you control gets +1/+1 and gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Guardian Gladewalker

Changeling (This card is every creature type.)
When Guardian Gladewalker enters the battlefield, put a +1/+1 counter on target creature.

Ivy Lane Denizen

Whenever another green creature enters the battlefield under your control, put a +1/+1 counter on target creature.