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.

Sunken Hollow

({T}: Add {U} or {B}.)
Sunken Hollow enters tapped unless you control two or more basic lands.

An Offer You Can't Refuse

Counter target noncreature spell. Its controller creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Sol Ring

Black Sun's Zenith

Put X -1/-1 counters on each creature. Shuffle Black Sun's Zenith into its owner's library.

Champion of Lambholt

Creatures with power less than Champion of Lambholt's power can't block creatures you control.
Whenever another creature you control enters, put a +1/+1 counter on Champion of Lambholt.

Vashta Nerada

Indestructible
Shadow (This creature can block or be blocked by only creatures with shadow.)
Morbid — At the beginning of each end step, if a creature died this turn, put a +1/+1 counter on Vashta Nerada.

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.)

Yawgmoth, Thran Physician

Protection from Humans
Pay 1 life, Sacrifice another creature: Put a -1/-1 counter on up to one target creature and draw a card.
{B}{B}, Discard a card: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Farseek

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

Boseiju, Who Endures

{T}: Add {G}.
Channel — {1}{G}, Discard Boseiju, Who Endures: Destroy target artifact, enchantment, or nonbasic land an opponent controls. That player may search their library for a land card with a basic land type, put it onto the battlefield, then shuffle. This ability costs {1} less to activate for each legendary creature you control.

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.

Shipwreck Marsh

Shipwreck Marsh enters tapped unless you control two or more other lands.
{T}: Add {U} or {B}.

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.)

Midnight Banshee

Wither (This deals damage to creatures in the form of -1/-1 counters.)
At the beginning of your upkeep, put a -1/-1 counter on each nonblack creature.

Hapatra, Vizier of Poisons

Whenever Hapatra, Vizier of Poisons deals combat damage to a player, you may put a -1/-1 counter on target creature.
Whenever you put one or more -1/-1 counters on a creature, create a 1/1 green Snake creature token with deathtouch.

Swamp

Arwen, Weaver of Hope

Each other creature you control enters with a number of additional +1/+1 counters on it equal to Arwen, Weaver of Hope's toughness.

Sword of Truth and Justice

Equipped creature gets +2/+2 and has protection from white and from blue.
Whenever equipped creature deals combat damage to a player, put a +1/+1 counter on a creature you control, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)
Equip {2}

Drowned Catacomb

Drowned Catacomb enters tapped unless you control an Island or a Swamp.
{T}: Add {U} or {B}.

Viral Drake

Flying
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
{3}{U}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Krosan Grip

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Destroy target artifact or enchantment.

Obelisk Spider

Reach
Whenever Obelisk Spider deals combat damage to a creature, put a -1/-1 counter on that creature.
Whenever you put one or more -1/-1 counters on a creature, each opponent loses 1 life and you gain 1 life.

Renata, Called to the Hunt

Renata's power is equal to your devotion to green. (Each {G} in the mana costs of permanents you control counts toward your devotion to green.)
Each other creature you control enters with an additional +1/+1 counter on it.

Loyal Guardian

Trample
Lieutenant — At the beginning of combat on your turn, if you control your commander, put a +1/+1 counter on each creature you control.

Vraska, Betrayal's Sting

Compleated ({B/P} can be paid with {B} or 2 life. If life was paid, this planeswalker enters with two fewer loyalty counters.)
0: You draw a card and you lose 1 life. Proliferate.
−2: Target creature becomes a Treasure artifact with "{T}, Sacrifice this artifact: Add one mana of any color" and loses all other card types and abilities.
−9: If target player has fewer than nine poison counters, they get a number of poison counters equal to the difference.

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.)

Contagion Engine

When Contagion Engine enters, put a -1/-1 counter on each creature target player controls.
{4}, {T}: Proliferate twice. (Choose any number of permanents and/or players, then give each another counter of each kind already there. Then do it again.)

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.

Command Tower

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

Morphic Pool

Morphic Pool enters tapped unless you have two or more opponents.
{T}: Add {U} or {B}.

Master Biomancer

Each other creature you control enters 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.

Damnation

Destroy all creatures. They can't be regenerated.

Court of Garenbrig

When Court of Garenbrig enters, you become the monarch.
At the beginning of your upkeep, distribute two +1/+1 counters among up to two target creatures. Then if you're the monarch, double the number of +1/+1 counters on each creature you control.

Spitting Dilophosaurus

Whenever Spitting Dilophosaurus enters or attacks, put a -1/-1 counter on up to one target creature.
Creatures your opponents control with -1/-1 counters on them can't block.

Heroic Intervention

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

Yavimaya, Cradle of Growth

Each land is a Forest in addition to its other land types.

Contagion Clasp

When Contagion Clasp enters, put a -1/-1 counter on target creature.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Island

Danny Pink

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
Creatures you control have "Whenever one or more counters are put on this creature for the first time each turn, draw a card."

Mikaeus, the Unhallowed

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
Whenever a Human deals damage to you, destroy it.
Other non-Human creatures you control get +1/+1 and have undying. (When a creature with undying 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.)

Generous Patron

When Generous Patron enters, support 2. (Put a +1/+1 counter on each of up to two other target creatures.)
Whenever you put one or more counters on a creature you don't control, draw a card.

Arcane Signet

Exotic Orchard

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

Kodama's Reach

Verdant Catacombs

{T}, Pay 1 life, Sacrifice Verdant Catacombs: Search your library for a Swamp or Forest card, put it onto the battlefield, then shuffle.

Cankerbloom

{1}, Sacrifice Cankerbloom: Choose one —
• Destroy target artifact.
• Destroy target enchantment.
• Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Clever Impersonator

You may have Clever Impersonator enter as a copy of any nonland permanent on the battlefield.

Progenitor Mimic

You may have Progenitor Mimic enter 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."

Tribute to the World Tree

Whenever a creature you control enters, draw a card if its power is 3 or greater. Otherwise, put two +1/+1 counters on it.

Carnifex Demon

Flying
Carnifex Demon enters with two -1/-1 counters on it.
{B}, Remove a -1/-1 counter from Carnifex Demon: Put a -1/-1 counter on each other creature.

Cauldron of Souls

{T}: Choose any number of target creatures. Each of those creatures gains persist until end of turn. (When it 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.)

Necroskitter

Wither (This deals damage to creatures in the form of -1/-1 counters.)
Whenever a creature an opponent controls with a -1/-1 counter on it dies, you may return that card to the battlefield under your control.

Tainted Observer

Flying
Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
Whenever another creature you control enters, you may pay {2}. If you do, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Opulent Palace

Opulent Palace enters tapped.
{T}: Add {B}, {G}, or {U}.

Forest

Rampant Growth

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

Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

Misty Rainforest

{T}, Pay 1 life, Sacrifice Misty Rainforest: Search your library for a Forest or Island card, put it onto the battlefield, then shuffle.

Rejuvenating Springs

Rejuvenating Springs enters tapped unless you have two or more opponents.
{T}: Add {G} or {U}.

Woodland Cemetery

Woodland Cemetery enters tapped unless you control a Swamp or a Forest.
{T}: Add {B} or {G}.

Scheming Aspirant

Whenever you proliferate, each opponent loses 2 life and you gain 2 life.

Nest of Scarabs

Whenever you put one or more -1/-1 counters on a creature, create that many 1/1 black Insect creature tokens.

Fathom Mage

Evolve (Whenever a creature you control enters, 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.

Volrath, the Shapestealer

At the beginning of combat on your turn, put a -1/-1 counter on up to one target creature.
{1}: Until your next turn, Volrath, the Shapestealer becomes a copy of target creature with a counter on it, except it's 7/5 and it has this ability.

Crumbling Ashes

At the beginning of your upkeep, destroy target creature with a -1/-1 counter on it.

Dreamroot Cascade

Dreamroot Cascade enters tapped unless you control two or more other lands.
{T}: Add {G} or {U}.

Zagoth Triome

({T}: Add {B}, {G}, or {U}.)
Zagoth Triome enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Devoted Druid

{T}: Add {G}.
Put a -1/-1 counter on Devoted Druid: Untap Devoted Druid.

Blowfly Infestation

Whenever a creature dies, if it had a -1/-1 counter on it, put a -1/-1 counter on target creature.

Deathcap Glade

Deathcap Glade enters tapped unless you control two or more other lands.
{T}: Add {B} or {G}.

Spark Double

You may have Spark Double enter as a copy of a creature or planeswalker you control, except it enters with an additional +1/+1 counter on it if it's a creature, it enters with an additional loyalty counter on it if it's a planeswalker, and it isn't legendary.

Polluted Delta

{T}, Pay 1 life, Sacrifice Polluted Delta: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Biophagus

Genomic Enhancement — {T}: Add one mana of any color. If this mana is spent to cast a creature spell, that creature enters with an additional +1/+1 counter on it.

Evolution Sage

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

Overgrown Tomb

({T}: Add {B} or {G}.)
As Overgrown Tomb enters, you may pay 2 life. If you don't, it enters tapped.

Breeding Pool

({T}: Add {G} or {U}.)
As Breeding Pool enters, you may pay 2 life. If you don't, it enters tapped.

Beast Within

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

The Ozolith

Whenever a creature you control leaves the battlefield, if it had counters on it, put those counters on The Ozolith.
At the beginning of combat on your turn, if The Ozolith has counters on it, you may move all counters from The Ozolith onto target creature.

Watery Grave

({T}: Add {U} or {B}.)
As Watery Grave enters, you may pay 2 life. If you don't, it enters tapped.

Wickerbough Elder

Wickerbough Elder enters with a -1/-1 counter on it.
{G}, Remove a -1/-1 counter from Wickerbough Elder: Destroy target artifact or enchantment.

Soul Diviner

{T}, Remove a counter from an artifact, creature, land, or planeswalker you control: Draw a card.

Grim Affliction

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.)

Steady Progress

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

Hinterland Harbor

Hinterland Harbor enters tapped unless you control a Forest or an Island.
{T}: Add {G} or {U}.

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.

Swan Song

Counter target enchantment, instant, or sorcery spell. Its controller creates a 2/2 blue Bird creature token with flying.

Undergrowth Stadium

Undergrowth Stadium enters tapped unless you have two or more opponents.
{T}: Add {B} or {G}.

Ezuri, Stalker of Spheres

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

Toxrill, the Corrosive

At the beginning of each end step, put a slime counter on each creature you don't control.
Creatures you don't control get -1/-1 for each slime counter on them.
Whenever a creature you don't control with a slime counter on it dies, create a 1/1 black Slug creature token.
{U}{B}, Sacrifice a Slug: Draw a card.