Keleth, Sunmane Familiar

Whenever a commander you control attacks, put a +1/+1 counter on it.
Partner (You can have two commanders if both have partner.)

Bioshift

Move any number of +1/+1 counters from target creature onto another target creature with the same controller.

Gnarlid Colony

Kicker {2}{G} (You may pay an additional {2}{G} as you cast this spell.)
If Gnarlid Colony was kicked, it enters the battlefield with two +1/+1 counters on it.
Each creature you control with a +1/+1 counter on it has trample.

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.

Scute Mob

At the beginning of your upkeep, if you control five or more lands, put four +1/+1 counters on Scute Mob.

Hall of Oracles

{T}: Add {C}.
{1}, {T}: Add one mana of any color.
{T}: Put a +1/+1 counter on target creature. Activate only as a sorcery and only if you've cast an instant or sorcery spell this turn.

Bramblewood Paragon

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

Curious Obsession

Enchant creature
Enchanted creature gets +1/+1 and has "Whenever this creature deals combat damage to a player, you may draw a card."
At the beginning of your end step, if you didn't attack with a creature this turn, sacrifice Curious Obsession.

Supply Runners

When Supply Runners enters the battlefield, put a +1/+1 counter on each other creature you control.

Lorescale Coatl

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

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}

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.

Daring Archaeologist

When Daring Archaeologist enters the battlefield, you may return target artifact card from your graveyard to your hand.
Whenever you cast a historic spell, put a +1/+1 counter on Daring Archaeologist. (Artifacts, legendaries, and Sagas are historic.)

Archangel of Thune

Flying
Lifelink (Damage dealt by this creature also causes you to gain that much life.)
Whenever you gain life, put a +1/+1 counter on each creature you control.

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.)

Vastwood Hydra

Vastwood Hydra enters the battlefield with X +1/+1 counters on it.
When Vastwood Hydra dies, you may distribute a number of +1/+1 counters equal to the number of +1/+1 counters on Vastwood Hydra among any number of creatures you control.

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.

Enduring Renewal

Play with your hand revealed.
If you would draw a card, reveal the top card of your library instead. If it's a creature card, put it into your graveyard. Otherwise, draw a card.
Whenever a creature is put into your graveyard from the battlefield, return it to your hand.

Mentor of the Meek

Whenever another creature with power 2 or less enters the battlefield under your control, you may pay {1}. If you do, draw a card.

Thought Sponge

Flash
Thought Sponge enters the battlefield with a number of +1/+1 counters on it equal to the greatest number of cards an opponent has drawn this turn.
When Thought Sponge dies, draw cards equal to its power.

Rushwood Elemental

Trample
At the beginning of your upkeep, you may put a +1/+1 counter on Rushwood Elemental.

Biogenic Ooze

When Biogenic Ooze enters the battlefield, create a 2/2 green Ooze creature token.
At the beginning of your end step, put a +1/+1 counter on each Ooze you control.
{1}{G}{G}{G}: Create a 2/2 green Ooze creature token.

Fearless Fledgling

Landfall — Whenever a land enters the battlefield under your control, put a +1/+1 counter on Fearless Fledgling. It gains flying until end of turn.

Snapping Sailback

Flash
Enrage — Whenever Snapping Sailback is dealt damage, put a +1/+1 counter on it. (It must survive the damage to get the counter.)

Tatyova, Benthic Druid

Landfall — Whenever a land enters the battlefield under your control, you gain 1 life and draw a card.

Lifeblood Hydra

Trample
Lifeblood Hydra enters the battlefield with X +1/+1 counters on it.
When Lifeblood Hydra dies, you gain life and draw cards equal to its power.

Toothy, Imaginary Friend

Partner with Pir, Imaginative Rascal (When this creature enters the battlefield, target player may put Pir into their hand from their library, then shuffle.)
Whenever you draw a card, put a +1/+1 counter on Toothy, Imaginary Friend.
When Toothy leaves the battlefield, draw a card for each +1/+1 counter on it.

Military Intelligence

Whenever you attack with two or more creatures, draw a card.

Kydele, Chosen of Kruphix

{T}: Add {C} for each card you've drawn this turn.
Partner (You can have two commanders if both have partner.)

Primordial Hydra

Primordial Hydra enters the battlefield with X +1/+1 counters on it.
At the beginning of your upkeep, double the number of +1/+1 counters on Primordial Hydra.
Primordial Hydra has trample as long as it has ten or more +1/+1 counters on it.

Guild Thief

Whenever Guild Thief deals combat damage to a player, put a +1/+1 counter on it.
Cunning Action — {3}{U}: Guild Thief can't be blocked this turn.

Ochre Jelly

Trample
Ochre Jelly enters the battlefield with X +1/+1 counters on it.
Split — When Ochre Jelly dies, if it had two or more +1/+1 counters on it, create a token that's a copy of it at the beginning of the next end step. The token enters the battlefield with half that many +1/+1 counters on it, rounded down.

Makeshift Battalion

Battalion — Whenever Makeshift Battalion and at least two other creatures attack, put a +1/+1 counter on Makeshift Battalion.

Tireless Provisioner

Landfall — Whenever a land enters the battlefield under your control, create a Food token or a Treasure token. (Food is an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life." Treasure is an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

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.

Sakashima of a Thousand Faces

You may have Sakashima of a Thousand Faces enter the battlefield as a copy of another creature you control, except it has Sakashima of a Thousand Faces's other abilities.
The "legend rule" doesn't apply to permanents you control.
Partner (You can have two commanders if both have partner.)

Ajani, Wise Counselor

+2: You gain 1 life for each creature you control.
−3: Creatures you control get +2/+2 until end of turn.
−9: Put X +1/+1 counters on target creature, where X is your life total.

Nessian Hornbeetle

At the beginning of combat on your turn, if you control another creature with power 4 or greater, put a +1/+1 counter on Nessian Hornbeetle.

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.

Call

Create four 1/1 white Bird creature tokens with flying.
Fuse (You may cast one or both halves of this card from your hand.)

Beck

Whenever a creature enters the battlefield this turn, you may draw a card.
Fuse (You may cast one or both halves of this card from your hand.)

Beck // Call

Dovescape

({W/U} can be paid with either {W} or {U}.)
Whenever a player casts a noncreature spell, counter that spell. That player creates X 1/1 white and blue Bird creature tokens with flying, where X is the spell's mana value.

Unruly Mob

Whenever another creature you control dies, put a +1/+1 counter on Unruly Mob.

Aesi, Tyrant of Gyre Strait

You may play an additional land on each of your turns.
Landfall — Whenever a land enters the battlefield under your control, you may draw a card.

Sunbond

Enchant creature
Enchanted creature has "Whenever you gain life, put that many +1/+1 counters on this creature."

Oran-Rief Hydra

Trample
Landfall — Whenever a land enters the battlefield under your control, put a +1/+1 counter on Oran-Rief Hydra. If that land is a Forest, put two +1/+1 counters on Oran-Rief Hydra instead.

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.

Wildwood Scourge

Wildwood Scourge enters the battlefield with X +1/+1 counters on it.
Whenever one or more +1/+1 counters are put on another non-Hydra creature you control, put a +1/+1 counter on Wildwood Scourge.

Herd Baloth

Whenever one or more +1/+1 counters are put on Herd Baloth, you may create a 4/4 green Beast creature token.

Arcbound Crusher

Trample
Whenever another artifact enters the battlefield, put a +1/+1 counter on Arcbound Crusher.
Modular 1 (This creature enters the battlefield with a +1/+1 counter on it. When it dies, you may put its +1/+1 counters on target artifact creature.)

Alharu, Solemn Ritualist

When Alharu, Solemn Ritualist enters the battlefield, put a +1/+1 counter on each of up to two other target creatures.
Whenever a nontoken creature you control with a +1/+1 counter on it dies, create a 1/1 white Spirit creature token with flying.
Partner (You can have two commanders if both have partner.)

Shabraz, the Skyshark

Partner with Brallin, Skyshark Rider
Flying
Whenever you draw a card, put a +1/+1 counter on Shabraz, the Skyshark and you gain 1 life.
{W/U}: Target Human gains flying until end of turn.

Zendikar's Roil

Landfall — Whenever a land enters the battlefield under your control, create a 2/2 green Elemental creature token.

Capricopian

Capricopian enters the battlefield with X +1/+1 counters on it.
{2}: Put a +1/+1 counter on Capricopian, then you may reselect which player Capricopian is attacking. Only the player Capricopian is attacking may activate this ability and only during the declare attackers step. (It can't attack its controller.)

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.

Guardian Kirin

Flying
Whenever another creature you control dies, put a +1/+1 counter on Guardian Kirin.

Diamond Knight

Vigilance (Attacking doesn't cause this creature to tap.)
As Diamond Knight enters the battlefield, choose a color.
Whenever you cast a spell of the chosen color, put a +1/+1 counter on Diamond Knight.

Vinelasher Kudzu

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

Ivy Lane Denizen

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

Vivien, Nature's Avenger

+1: Put three +1/+1 counters on up to one target creature.
−1: Reveal cards from the top of your library until you reveal a creature card. Put that card into your hand and the rest on the bottom of your library in a random order.
−6: Target creature gets +10/+10 and gains trample 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.

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.

Elspeth, Undaunted Hero

+2: Put a +1/+1 counter on each of up to two target creatures.
−2: Search your library and/or graveyard for a card named Sunlit Hoplite and put it onto the battlefield. If you search your library this way, shuffle.
−8: Until end of turn, creatures you control gain flying and get +X/+X, where X is your devotion to white.

Phantom Flock

Flying
Phantom Flock enters the battlefield with three +1/+1 counters on it.
If damage would be dealt to Phantom Flock, prevent that damage. Remove a +1/+1 counter from Phantom Flock.

Sapphire Drake

Flying
Each creature you control with a +1/+1 counter on it has flying.

Oko, the Trickster

+1: Put two +1/+1 counters on up to one target creature you control.
0: Until end of turn, Oko, the Trickster becomes a copy of target creature you control. Prevent all damage that would be dealt to him this turn.
−7: Until end of turn, each creature you control has base power and toughness 10/10 and gains trample.

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.

Brineborn Cutthroat

Flash (You may cast this spell any time you could cast an instant.)
Whenever you cast a spell during an opponent's turn, put a +1/+1 counter on Brineborn Cutthroat.

Arcbound Slith

Whenever Arcbound Slith deals combat damage to a player, put a +1/+1 counter on it.
Modular 1 (This creature enters the battlefield with a +1/+1 counter on it. When it dies, you may put its +1/+1 counters on target artifact creature.)

Crowned Ceratok

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

Faerie Vandal

Flash
Flying
Whenever you draw your second card each turn, put a +1/+1 counter on Faerie Vandal.

Celestial Ancient

Flying
Whenever you cast an enchantment spell, put a +1/+1 counter on each creature you control.

Ajani, Valiant Protector

+2: Put two +1/+1 counters on up to one target creature.
+1: Reveal cards from the top of your library until you reveal a creature card. Put that card into your hand and the rest on the bottom of your library in a random order.
−11: Put X +1/+1 counters on target creature, where X is your life total. That creature gains trample until end of turn.

Basri Ket

+1: Put a +1/+1 counter on up to one target creature. It gains indestructible until end of turn.
−2: Whenever one or more nontoken creatures attack this turn, create that many 1/1 white Soldier creature tokens that are tapped and attacking.
−6: You get an emblem with "At the beginning of combat on your turn, create a 1/1 white Soldier creature token, then put a +1/+1 counter on each creature you control."

Untethered Express

Trample
Whenever Untethered Express attacks, put a +1/+1 counter on it.
Crew 1 (Tap any number of creatures you control with total power 1 or more: This Vehicle becomes an artifact creature until end of turn.)

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.

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.

Phantom Nantuko

Trample
Phantom Nantuko enters the battlefield with two +1/+1 counters on it.
If damage would be dealt to Phantom Nantuko, prevent that damage. Remove a +1/+1 counter from Phantom Nantuko.
{T}: Put a +1/+1 counter on Phantom Nantuko.

Nissa, Voice of Zendikar

+1: Create a 0/1 green Plant creature token.
−2: Put a +1/+1 counter on each creature you control.
−7: You gain X life and draw X cards, where X is the number of lands you control.

Good-Fortune Unicorn

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

Quest for Renewal

Whenever a creature you control becomes tapped, you may put a quest counter on Quest for Renewal.
As long as there are four or more quest counters on Quest for Renewal, untap all creatures you control during each other player's untap step.

Kurgadon

Whenever you cast a creature spell with mana value 6 or greater, put three +1/+1 counters on Kurgadon.

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.

Kalonian Hydra

Trample
Kalonian Hydra enters the battlefield with four +1/+1 counters on it.
Whenever Kalonian Hydra attacks, double the number of +1/+1 counters on each creature you control.

Shalai, Voice of Plenty

Flying
You, planeswalkers you control, and other creatures you control have hexproof.
{4}{G}{G}: Put a +1/+1 counter on each creature you control.

Take

Remove all +1/+1 counters from target creature you control. Draw that many cards.
Fuse (You may cast one or both halves of this card from your hand.)

Give

Put three +1/+1 counters on target creature.
Fuse (You may cast one or both halves of this card from your hand.)

Give // Take

Monk of the Open Hand

Flurry of Blows — Whenever you cast your second spell each turn, put a +1/+1 counter on Monk of the Open Hand.

Thundering Mightmare

Soulbond (You may pair this creature with another unpaired creature when either enters the battlefield. They remain paired for as long as you control both of them.)
As long as Thundering Mightmare is paired with another creature, each of those creatures has "Whenever an opponent casts a spell, put a +1/+1 counter on this creature."

Ragnar

{G}{W}{U}, {T}: Regenerate target creature.

Slith Predator

Trample
Whenever Slith Predator deals combat damage to a player, put a +1/+1 counter on it.

Kavu Predator

Trample
Whenever an opponent gains life, put that many +1/+1 counters on Kavu Predator.

Ironscale Hydra

If a creature would deal combat damage to Ironscale Hydra, prevent that damage and put a +1/+1 counter on Ironscale Hydra.

Fractal Summoning

Create a 0/0 green and blue Fractal creature token. Put X +1/+1 counters on it.

Basri, Devoted Paladin

+1: Put a +1/+1 counter on up to one target creature. It gains vigilance until end of turn.
−1: Whenever a creature attacks this turn, put a +1/+1 counter on it.
−6: Creatures you control get +2/+2 and gain flying until end of turn.

Retreat to Emeria

Landfall — Whenever a land enters the battlefield under your control, choose one —
• Create a 1/1 white Kor Ally creature token.
• Creatures you control get +1/+1 until end of turn.

Lathiel, the Bounteous Dawn

Lifelink
At the beginning of each end step, if you gained life this turn, distribute up to that many +1/+1 counters among any number of other target creatures.

Cazur, Ruthless Stalker

Partner with Ukkima, Stalking Shadow (When this creature enters the battlefield, target player may put Ukkima into their hand from their library, then shuffle.)
Whenever a creature you control deals combat damage to a player, put a +1/+1 counter on that creature.

Ajani's Comrade

Trample
At the beginning of combat on your turn, if you control an Ajani planeswalker, put a +1/+1 counter on Ajani's Comrade.

Predatory Hunger

Enchant creature
Whenever an opponent casts a creature spell, put a +1/+1 counter on enchanted creature.