Forest

Frilled Mystic

Flash
When Frilled Mystic enters the battlefield, you may counter target spell.

Trygon Predator

Flying
Whenever Trygon Predator deals combat damage to a player, you may destroy target artifact or enchantment that player controls.

Soul's Might

Put X +1/+1 counters on target creature, where X is that creature's power.

Applied Biomancy

Choose one or both —
• Target creature gets +1/+1 until end of turn.
• Return target creature to its owner's hand.

Grafted Exoskeleton

Equipped creature gets +2/+2 and has infect. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Whenever Grafted Exoskeleton becomes unattached from a permanent, sacrifice that permanent.
Equip {2}

Neoform

As an additional cost to cast this spell, sacrifice a creature.
Search your library for a creature card with mana value equal to 1 plus the sacrificed creature's mana value, put that card onto the battlefield with an additional +1/+1 counter on it, then shuffle.

Island

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.

Explosive Vegetation

Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Blightwidow

Reach (This creature can block creatures with flying.)
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Simic Guildgate

Simic Guildgate enters the battlefield tapped.
{T}: Add {G} or {U}.

Cloudfin Raptor

Flying
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.)

Evolving Wilds

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

Galloping Lizrog

Trample
When Galloping Lizrog enters the battlefield, you may remove any number of +1/+1 counters from among creatures you control. If you do, put twice that many +1/+1 counters on Galloping Lizrog.

Fuel for the Cause

Counter target spell, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Guardian Project

Whenever a nontoken creature enters the battlefield under your control, if it doesn't have the same name as another creature you control or a creature card in your graveyard, draw a card.

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.

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.

Vinelasher Kudzu

Landfall — Whenever a land enters the battlefield under your control, put a +1/+1 counter on Vinelasher Kudzu.

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.

Progenitor Mimic

You may have Progenitor Mimic enter the battlefield as a copy of any creature on the battlefield, except it has "At the beginning of your upkeep, if this creature isn't a token, create a token that's a copy of this creature."

Omnibian

{T}: Target creature becomes a Frog with base power and toughness 3/3 until end of turn.

Voidslime

Counter target spell, activated ability, or triggered ability. (Mana abilities can't be targeted.)

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.

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.)

Rot Shambler

Whenever another creature you control dies, put a +1/+1 counter on Rot Shambler.

Urban Evolution

Draw three cards. You may play an additional land this turn.

Holdout Settlement

{T}: Add {C}. ({C} represents colorless mana.)
{T}, Tap an untapped creature you control: Add one mana of any color.

Essence Scatter

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.)

Negate

Skarrgan Pit-Skulk

Bloodthirst 1 (If an opponent was dealt damage this turn, this creature enters the battlefield with a +1/+1 counter on it.)
Creatures with power less than Skarrgan Pit-Skulk's power can't block it.

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.

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.

Shrine of Boundless Growth

At the beginning of your upkeep or whenever you cast a green spell, put a charge counter on Shrine of Boundless Growth.
{T}, Sacrifice Shrine of Boundless Growth: Add {C} for each charge counter on Shrine of Boundless Growth.

Catalog

Tel-Jilad Fallen

Protection from artifacts
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Grunn, the Lonely King

Kicker {3} (You may pay an additional {3} as you cast this spell.)
If Grunn, the Lonely King was kicked, it enters the battlefield with five +1/+1 counters on it.
Whenever Grunn attacks alone, double its power and toughness until end of turn.

Simic Growth Chamber

Simic Growth Chamber enters the battlefield tapped.
When Simic Growth Chamber enters the battlefield, return a land you control to its owner's hand.
{T}: Add {G}{U}.

Skyline Cascade

Skyline Cascade enters the battlefield tapped.
When Skyline Cascade enters the battlefield, target creature an opponent controls doesn't untap during its controller's next untap step.
{T}: Add {U}.

Haunted Fengraf

{T}: Add {C}.
{3}, {T}, Sacrifice Haunted Fengraf: Return a creature card at random from your graveyard to your hand.

Desert of the Indomitable

Desert of the Indomitable enters the battlefield tapped.
{T}: Add {G}.
Cycling {1}{G} ({1}{G}, Discard this card: Draw a card.)

Nimbus Swimmer

Flying
Nimbus Swimmer enters the battlefield with X +1/+1 counters on it.

Gilded Lotus

Rishkar, Peema Renegade

When Rishkar, Peema Renegade enters the battlefield, 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}."

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."

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.

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.)

Woodland Stream

Woodland Stream enters the battlefield tapped.
{T}: Add {G} or {U}.

Simic Signet

Simic Sky Swallower

Flying, trample
Shroud (This creature can't be the target of spells or abilities.)

Miming Slime

Create an X/X green Ooze creature token, where X is the greatest power among creatures you control.

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.

Vorel of the Hull Clade

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

Herald of Secret Streams

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

Baloth Pup

Baloth Pup has trample as long as it has a +1/+1 counter on it.

Primal Wellspring

(Transforms from Primal Amulet.)
{T}: Add one mana of any color. When that mana is spent to cast an instant or sorcery spell, copy that spell and you may choose new targets for the copy.

Primal Amulet

Instant and sorcery spells you cast cost {1} less to cast.
Whenever you cast an instant or sorcery spell, put a charge counter on Primal Amulet. Then if there are four or more charge counters on it, you may remove those counters and transform it.

Primal Amulet // Primal Wellspring

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.

Elusive Krasis

Elusive Krasis can't be blocked.
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.)

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.)

Blighted Woodland

{T}: Add {C}.
{3}{G}, {T}, Sacrifice Blighted Woodland: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

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.

Fertile Thicket

Fertile Thicket enters the battlefield tapped.
When Fertile Thicket enters the battlefield, you may look at the top five cards of your library. If you do, reveal up to one basic land card from among them, then put that card on top of your library and the rest on the bottom in any order.
{T}: Add {G}.

Rapid Hybridization

Destroy target creature. It can't be regenerated. That creature's controller creates a 3/3 green Frog Lizard creature token.

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.

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.)

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.)