Plaxcaster Frogling

Graft 3 (This creature enters the battlefield with three +1/+1 counters on it. Whenever another creature enters the battlefield, you may move a +1/+1 counter from this creature onto it.)
{2}: Target creature with a +1/+1 counter on it gains shroud until end of turn. (It can't be the target of spells or abilities.)

Llanowar Reborn

Llanowar Reborn enters the battlefield tapped.
{T}: Add {G}.
Graft 1 (This land enters the battlefield with a +1/+1 counter on it. Whenever a creature enters the battlefield, you may move a +1/+1 counter from this land onto it.)

Vivisurgeon's Insight

Draw three cards. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Lorescale Coatl

Whenever you draw a card, put a +1/+1 counter on Lorescale Coatl.

Forced Adaptation

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

Unnatural Restoration

Return target permanent card from your graveyard to your hand. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Vorel of the Hull Clade

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

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.

Master Biomancer

Each other creature you control enters the battlefield with a number of additional +1/+1 counters on it equal to Master Biomancer's power and as a Mutant in addition to its other types.

Negate

Paradox Zone

Paradox Zone enters the battlefield with a growth counter on it.
At the beginning of your end step, double the number of growth counters on Paradox Zone. Then create a 0/0 green and blue Fractal creature token. Put X +1/+1 counters on it, where X is the number of growth counters on Paradox Zone.

Bred for the Hunt

Whenever a creature you control with a +1/+1 counter on it deals combat damage to a player, you may draw a card.

Renegade Krasis

Evolve (Whenever a creature enters the battlefield under your control, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)
Whenever Renegade Krasis evolves, put a +1/+1 counter on each other creature you control with a +1/+1 counter on it.

Prime Speaker Zegana

Prime Speaker Zegana enters the battlefield with X +1/+1 counters on it, where X is the greatest power among other creatures you control.
When Prime Speaker Zegana enters the battlefield, draw cards equal to its power.

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.

Fathom Mage

Evolve (Whenever a creature enters the battlefield under your control, 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.

Evolving Wilds

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

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.)

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

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.

Contentious Plan

Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)
Draw a card.

Mosswort Bridge

Hideaway 4 (When this land enters the battlefield, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.)
Mosswort Bridge enters the battlefield tapped.
{T}: Add {G}.
{G}, {T}: You may play the exiled card without paying its mana cost if creatures you control have total power 10 or greater.

Fractal Harness

When Fractal Harness enters the battlefield, create a 0/0 green and blue Fractal creature token. Put X +1/+1 counters on it and attach Fractal Harness to it.
Whenever equipped creature attacks, double the number of +1/+1 counters on it.
Equip {2}

Three Visits

Search your library for a Forest card, put it onto the battlefield, then shuffle.

Kami of Whispered Hopes

If one or more +1/+1 counters would be put on a permanent you control, that many plus one +1/+1 counters are put on that permanent instead.
{T}: Add X mana of any one color, where X is Kami of Whispered Hopes's power.

Herald of Secret Streams

Creatures you control with +1/+1 counters on them can't be blocked.

Beast Within

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

Merfolk Skydiver

Flying
When Merfolk Skydiver enters the battlefield, put a +1/+1 counter on target creature you control.
{3}{G}{U}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Arcane Signet

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

Oran-Rief, the Vastwood

Oran-Rief, the Vastwood enters the battlefield tapped.
{T}: Add {G}.
{T}: Put a +1/+1 counter on each green creature that entered the battlefield this turn.

Zegana, Utopian Speaker

When Zegana, Utopian Speaker enters the battlefield, if you control another creature with a +1/+1 counter on it, draw a card.
{4}{G}{U}: Adapt 4. (If this creature has no +1/+1 counters on it, put four +1/+1 counters on it.)
Each creature you control with a +1/+1 counter on it has trample.

Oversimplify

Exile all creatures. Each player creates a 0/0 green and blue Fractal creature token and puts a number of +1/+1 counters on it equal to the total power of creatures they controlled that were exiled this way.

Kodama's Reach

Command Tower

Sol Ring

Branching Evolution

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

Sage of Hours

Heroic — Whenever you cast a spell that targets Sage of Hours, put a +1/+1 counter on it.
Remove all +1/+1 counters from Sage of Hours: For each five counters removed this way, take an extra turn after this one.

Ozolith, the Shattered Spire

If one or more +1/+1 counters would be put on an artifact or creature you control, that many plus one +1/+1 counters are put on it instead.
{1}{G}, {T}: Put a +1/+1 counter on target artifact or creature you control. Activate only as a sorcery.
Cycling {2} ({2}, Discard this card: Draw a card.)

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.

Terramorphic Expanse

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

Farseek

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

Tyranid Prime

Evolve (Whenever a creature enters the battlefield under your control, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)
Synapse Creature — Other creatures you control have evolve.

Thought Vessel

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

Zameck Guildmage

{G}{U}: This turn, each creature you control enters the battlefield with an additional +1/+1 counter on it.
{G}{U}, Remove a +1/+1 counter from a creature you control: Draw a card.

Biomancer's Familiar

Activated abilities of creatures you control cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.
{T}: The next time target creature adapts this turn, it adapts as though it had no +1/+1 counters on it.

Exotic Orchard

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

Tekuthal, Inquiry Dominus

Flying
If you would proliferate, proliferate twice instead.
{1}{U/P}{U/P}, Remove three counters from among other artifacts, creatures, and planeswalkers you control: Put an indestructible counter on Tekuthal, Inquiry Dominus. ({U/P} can be paid with either {U} or 2 life.)

Experiment One

Evolve (Whenever a creature enters the battlefield under your control, 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.)

Momir Vig, Simic Visionary

Whenever you cast a green creature spell, you may search your library for a creature card, reveal it, then shuffle and put that card on top.
Whenever you cast a blue creature spell, reveal the top card of your library. If it's a creature card, put that card into your hand.

Ezuri, Stalker of Spheres

When Ezuri, Stalker of Spheres enters the battlefield, you may pay {3}. If you do, proliferate twice.
Whenever you proliferate, draw a card.

Karn's Bastion

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

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.)

Heroic Intervention

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

Rampant Growth

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

Tanazir Quandrix

Flying, trample
When Tanazir Quandrix enters the battlefield, double the number of +1/+1 counters on target creature you control.
Whenever Tanazir Quandrix attacks, you may have the base power and toughness of other creatures you control become equal to Tanazir Quandrix's power and toughness until end of turn.

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

Island

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Managorger Hydra

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

Skatewing Spy

{5}{U}: Adapt 2. (If this creature has no +1/+1 counters on it, put two +1/+1 counters on it.)
Each creature you control with a +1/+1 counter on it has flying.

Armorcraft Judge

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

Gyre Sage

Evolve (Whenever a creature enters the battlefield under your control, 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.

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.)

Counterspell

Experimental Augury

Look at the top three cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Cytoplast Root-Kin

Graft 4 (This creature enters the battlefield with four +1/+1 counters on it. Whenever another creature enters the battlefield, you may move a +1/+1 counter from this creature onto it.)
When Cytoplast Root-Kin enters the battlefield, put a +1/+1 counter on each other creature you control with a +1/+1 counter on it.
{2}: Move a +1/+1 counter from target creature you control onto Cytoplast Root-Kin.

Master Chef

Commander creatures you own have "This creature enters the battlefield with an additional +1/+1 counter on it" and "Other creatures you control enter the battlefield with an additional +1/+1 counter on them."

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.)

Roalesk, Apex Hybrid

Flying, trample
When Roalesk, Apex Hybrid enters the battlefield, put two +1/+1 counters on another target creature you control.
When Roalesk dies, proliferate, then proliferate again. (Choose any number of permanents and/or players, then give each another counter of each kind already there. Then do it again.)

Thrummingbird

Flying
Whenever Thrummingbird deals combat damage to a player, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Forest

Simic Ascendancy

{1}{G}{U}: Put a +1/+1 counter on target creature you control.
Whenever one or more +1/+1 counters are put on a creature you control, put that many growth counters on Simic Ascendancy.
At the beginning of your upkeep, if Simic Ascendancy has twenty or more growth counters on it, you win the game.

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.)

Fight Rigging

Hideaway 5 (When this enchantment enters the battlefield, look at the top five cards of your library, exile one face down, then put the rest on the bottom in a random order.)
At the beginning of combat on your turn, put a +1/+1 counter on target creature you control. Then if you control a creature with power 7 or greater, you may play the exiled card without paying its mana cost.

Experiment Kraj

Experiment Kraj has all activated abilities of each other creature with a +1/+1 counter on it.
{T}: Put a +1/+1 counter on target creature.

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.