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.)

Frostweb Spider

Reach (This creature can block creatures with flying.)
Whenever Frostweb Spider blocks a creature with flying, put a +1/+1 counter on Frostweb Spider at end of combat.

Forced Adaptation

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

Fake Your Own Death

Until end of turn, target creature gets +2/+0 and gains "When this creature dies, return it to the battlefield tapped under its owner's control and you create a Treasure token." (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

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.

Evolution Witness

{1}{G}: Adapt 2. (If this creature has no +1/+1 counters on it, put two +1/+1 counters on it.)
Whenever one or more +1/+1 counters are put on Evolution Witness, return target permanent card from your graveyard to your hand.

Stony Strength

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

Stronghold Confessor

Kicker {3} (You may pay an additional {3} as you cast this spell.)
Menace (This creature can't be blocked except by two or more creatures.)
If Stronghold Confessor was kicked, it enters the battlefield with two +1/+1 counters on it.

Scale Deflection

Put two +1/+1 counters on target creature and untap it. It gains hexproof until end of turn. (Then exile this card. You may cast the creature later from exile.)

Dread Linnorm

Dread Linnorm can't be blocked by creatures with power 3 or less.

Dread Linnorm // Scale Deflection

Retrofitted Transmogrant

{3}{B}: Return Retrofitted Transmogrant from your graveyard to the battlefield tapped with two +1/+1 counters on it.

Dig Deep

Choose target creature. Mill four cards, then put a +1/+1 counter on that creature for each creature card milled this way.

Colossal Badger

When Colossal Badger enters the battlefield, you gain 3 life.

Colossal Badger // Dig Deep

Witch's Cottage

({T}: Add {B}.)
Witch's Cottage enters the battlefield tapped unless you control three or more other Swamps.
When Witch's Cottage enters the battlefield untapped, you may put target creature card from your graveyard on top of your library.

Formless Nurturing

Manifest the top card of your library, then put a +1/+1 counter on it. (To manifest a card, put it onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)

Soul's Might

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

Lethal Sting

As an additional cost to cast this spell, put a -1/-1 counter on a creature you control.
Destroy target creature.

Duskshell Crawler

When Duskshell Crawler enters the battlefield, put a +1/+1 counter on target creature.
Each creature you control with a +1/+1 counter on it has trample.

Trufflesnout

When Trufflesnout enters the battlefield, choose one —
• Put a +1/+1 counter on Trufflesnout.
• You gain 4 life.

Primal Cocoon

Enchant creature
At the beginning of your upkeep, put a +1/+1 counter on enchanted creature.
When enchanted creature attacks or blocks, sacrifice Primal Cocoon.

Elves of Deep Shadow

{T}: Add {B}. Elves of Deep Shadow deals 1 damage to you.

Festercreep

Festercreep enters the battlefield with a +1/+1 counter on it.
{1}{B}, Remove a +1/+1 counter from Festercreep: All other creatures get -1/-1 until end of turn.

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.

Smell Fear

Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)
Target creature you control fights up to one target creature you don't control.

Expanding Ooze

{B}{G}: Adapt 1. (If this creature has no +1/+1 counters on it, put a +1/+1 counter on it.)
Whenever Expanding Ooze attacks, put a +1/+1 counter on target modified creature you control. (Equipment, Auras you control, and counters are modifications.)

Aerie Ouphes

Sacrifice Aerie Ouphes: It deals damage equal to its power to target creature with flying.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Oaken Boon

Put two +1/+1 counters on target creature. (Then exile this card. You may cast the creature later from exile.)

Tuinvale Treefolk

Tuinvale Treefolk // Oaken Boon

Blood Researcher

Menace (This creature can't be blocked except by two or more creatures.)
Whenever you gain life, put a +1/+1 counter on Blood Researcher.

Mold Folk

Lifelink
Mold Harvest — {1}, Sacrifice another creature or an artifact: Put a +1/+1 counter on Mold Folk.

Nature's Lore

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

Gavony Unhallowed

Whenever another creature you control dies, put a +1/+1 counter on Gavony Unhallowed.

Unearth

Return target creature card with mana value 3 or less from your graveyard to the battlefield.
Cycling {2} ({2}, Discard this card: Draw a card.)

Crypt Rats

{X}: Crypt Rats deals X damage to each creature and each player. Spend only black mana on X.

Dauntless Survivor

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

Oblivion's Hunger

Target creature you control gains indestructible until end of turn. Draw a card if that creature has a +1/+1 counter on it. (Damage and effects that say "destroy" don't destroy the creature.)

Grafted Growth

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

Infuse with Vitality

Until end of turn, target creature gains deathtouch and "When this creature dies, return it to the battlefield tapped under its owner's control."
You gain 2 life.

Ivy Elemental

Ivy Elemental enters the battlefield with X +1/+1 counters on it.

Crocanura

Reach (This creature can block creatures with 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.)

Adaptive Snapjaw

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.)

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.)

Forest

Undercity Scavenger

When Undercity Scavenger enters the battlefield, you may sacrifice another creature. If you do, put two +1/+1 counters on Undercity Scavenger, then scry 2.

Wither and Bloom

Target creature gets -3/-3 until end of turn.
{1}{B}, Exile Wither and Bloom from your graveyard: Put a +1/+1 counter on target creature you control. Activate only as a sorcery.

Khalni Garden

Khalni Garden enters the battlefield tapped.
When Khalni Garden enters the battlefield, create a 0/1 green Plant creature token.
{T}: Add {G}.

Gnarlid Pack

Multikicker {1}{G} (You may pay an additional {1}{G} any number of times as you cast this spell.)
Gnarlid Pack enters the battlefield with a +1/+1 counter on it for each time it was kicked.

Reckoner's Bargain

As an additional cost to cast this spell, sacrifice an artifact or creature.
You gain life equal to the sacrificed permanent's mana value. Draw two cards.

Tunnel Tipster

At the beginning of your end step, if a face-down creature entered the battlefield under your control this turn, put a +1/+1 counter on Tunnel Tipster.
{T}: Add {G}.

Struggle for Skemfar

Put a +1/+1 counter on target creature you control. Then that creature fights up to one target creature you don't control. (Each deals damage equal to its power to the other.)
Foretell {G} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Scale the Heights

Put a +1/+1 counter on up to one target creature. You gain 2 life. You may play an additional land this turn.
Draw a card.

Carrion Feeder

Carrion Feeder can't block.
Sacrifice a creature: Put a +1/+1 counter on Carrion Feeder.

Sadistic Glee

Enchant creature
Whenever a creature dies, put a +1/+1 counter on enchanted creature.

Hunter's Edge

Put a +1/+1 counter on target creature you control. Then that creature deals damage equal to its power to target creature you don't control.

Predatory Hunger

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

Pestilence

At the beginning of the end step, if no creatures are on the battlefield, sacrifice Pestilence.
{B}: Pestilence deals 1 damage to each creature and each player.

Chance-Met Elves

Whenever you scry, put a +1/+1 counter on Chance-Met Elves. This ability triggers only once each turn.

Ulvenwald Bear

Morbid — When Ulvenwald Bear enters the battlefield, if a creature died this turn, put two +1/+1 counters on target creature.

Rhizome Lurcher

Undergrowth — Rhizome Lurcher enters the battlefield with a number of +1/+1 counters on it equal to the number of creature cards in your graveyard.

Voracious Null

{1}{B}, Sacrifice another creature: Put two +1/+1 counters on Voracious Null. Activate only as a sorcery.

Malevolent Noble

{2}, Sacrifice an artifact or another creature: Put a +1/+1 counter on Malevolent Noble.

Arcbound Worker

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.)

Farhaven Elf

When Farhaven Elf enters the battlefield, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Elvish Vanguard

Whenever another Elf enters the battlefield, put a +1/+1 counter on Elvish Vanguard.

Path of Ancestry

Path of Ancestry enters the battlefield tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Llanowar Elves

Essence Warden

Whenever another creature enters the battlefield, you gain 1 life.

Crawl from the Cellar

Return target creature card from your graveyard to your hand. Put a +1/+1 counter on up to one target Zombie you control.
Flashback {3}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

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.)

Wayfarer's Bauble

{2}, {T}, Sacrifice Wayfarer's Bauble: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Urban Daggertooth

Vigilance
Enrage — Whenever Urban Daggertooth is dealt damage, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Burst of Strength

Put a +1/+1 counter on target creature and untap it.

Caustic Caterpillar

{1}{G}, Sacrifice Caustic Caterpillar: Destroy target artifact or enchantment.

Deep Goblin Skulltaker

Menace
At the beginning of your end step, if you descended this turn, put a +1/+1 counter on Deep Goblin Skulltaker. (You descended if a permanent card was put into your graveyard from anywhere.)

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.)

Undying Malice

Until end of turn, target creature gains "When this creature dies, return it to the battlefield tapped under its owner's control with a +1/+1 counter on it."

Thirsting Roots

Choose one —
• Search your library for a basic land card, reveal it, put it into your hand, then shuffle.
• Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

The Hunter Maze

The Hunter Maze enters the battlefield tapped.
{T}: Add {G}.
{1}{G}, {T}, Sacrifice The Hunter Maze: Draw a card.

Bloom Hulk

When Bloom Hulk enters the battlefield, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Tragic Slip

Target creature gets -1/-1 until end of turn.
Morbid — That creature gets -13/-13 until end of turn instead if a creature died this turn.

Blightbelly Rat

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
When Blightbelly Rat dies, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Splendid Agony

Distribute two -1/-1 counters among one or two target creatures.

Entourage of Trest

When Entourage of Trest enters the battlefield, you become the monarch.
Entourage of Trest can block an additional creature each combat as long as you're the monarch.

Festerhide Boar

Trample
Morbid — Festerhide Boar enters the battlefield with two +1/+1 counters on it if a creature died this turn.

Command Tower

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

Coiling Stalker

Ninjutsu {1}{G} ({1}{G}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Coiling Stalker deals combat damage to a player, put a +1/+1 counter on target creature you control that doesn't have a +1/+1 counter on it.

Witherbloom Campus

Witherbloom Campus enters the battlefield tapped.
{T}: Add {B} or {G}.
{4}, {T}: Scry 1.

Thorn of the Black Rose

Deathtouch
When Thorn of the Black Rose enters the battlefield, you become the monarch.

Ent's Fury

Put a +1/+1 counter on target creature you control if its power is 4 or greater. Then that creature gets +1/+1 until end of turn and fights target creature you don't control.

Supernatural Stamina

Until end of turn, target creature gets +2/+0 and gains "When this creature dies, return it to the battlefield tapped under its owner's control."

Caldaia Strongarm

When Caldaia Strongarm enters the battlefield, put two +1/+1 counters on target creature.
Blitz {3}{G} (If you cast this spell for its blitz cost, it gains haste and "When this creature dies, draw a card." Sacrifice it at the beginning of the next end step.)

Nyxborn Hydra

Bestow {X}{G}{G} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached.)
Reach, trample
Nyxborn Hydra enters the battlefield with X +1/+1 counters on it.
Enchanted creature gets +1/+1 for each +1/+1 counter on Nyxborn Hydra and has reach and trample.

Masked Vandal

Changeling (This card is every creature type.)
When Masked Vandal enters the battlefield, you may exile a creature card from your graveyard. If you do, exile target artifact or enchantment an opponent controls.

Ironshell Beetle

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

Copper Longlegs

Reach
{1}{G}, Sacrifice Copper Longlegs: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Locthwain Paladin

Menace (This creature can't be blocked except by two or more creatures.)
Adamant — If at least three black mana was spent to cast this spell, Locthwain Paladin enters the battlefield with a +1/+1 counter on it.

Graypelt Hunter

Trample
Whenever Graypelt Hunter or another Ally enters the battlefield under your control, you may put a +1/+1 counter on Graypelt Hunter.

Unholy Indenture

Enchant creature
When enchanted creature dies, return that card to the battlefield under your control with a +1/+1 counter on it.

Dragonscale Boon

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

Henge Walker

Adamant — If at least three mana of the same color was spent to cast this spell, Henge Walker enters the battlefield with a +1/+1 counter on it.

Kavu Primarch

Kicker {4} (You may pay an additional {4} as you cast this spell.)
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.)
If Kavu Primarch was kicked, it enters the battlefield with four +1/+1 counters on it.