Thrummingbird

Flying
Whenever this creature 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.)

Infectious Bite

Target creature you control deals damage equal to its power to target creature you don't control. Each opponent gets a poison counter.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

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.

Merfolk Skydiver

Flying
When this creature enters, 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.)

Blight Mamba

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
{1}{G}: Regenerate this creature.

Sol Ring

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.)

Corrupted Conscience

Enchant creature
You control enchanted creature.
Enchanted creature has infect. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Prologue to Phyresis

Each opponent gets a poison counter.
Draw a card.

Opulent Palace

This land enters tapped.
{T}: Add {B}, {G}, or {U}.

Viridian Corrupter

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
When Viridian Corrupter enters, destroy target artifact.

Blightbelly Rat

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

Tetzimoc, Primal Death

Deathtouch
{B}, Reveal this card from your hand: Put a prey counter on target creature. Activate only during your turn.
When Tetzimoc enters, destroy each creature your opponents control with a prey counter on it.

Pestilent Syphoner

Flying
Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)

Venser, Corpse Puppet

Lifelink, toxic 1
Whenever you proliferate, choose one —
• If you don't control a creature named The Hollow Sentinel, create The Hollow Sentinel, a legendary 3/3 colorless Phyrexian Golem artifact creature token.
• Target artifact creature you control gains flying and lifelink until end of turn.

Temple of Mystery

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {G} or {U}.

Rishkar, Peema Renegade

When Rishkar enters, 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}."

Forgotten Ancient

Whenever a player casts a spell, you may put a +1/+1 counter on this creature.
At the beginning of your upkeep, you may move any number of +1/+1 counters from this creature onto other creatures.

Wickerbough Elder

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

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 this creature, you may draw a card.

Expand the Sphere

Look at the top six cards of your library. Put up to two land cards from among them onto the battlefield tapped and the rest on the bottom of your library in a random order. If you put fewer than two lands onto the battlefield this way, proliferate a number of times equal to the difference. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Jungle Hollow

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {B} or {G}.

Putrefy

Destroy target artifact or creature. It can't be regenerated.

Sultai Charm

Choose one —
• Destroy target monocolored creature.
• Destroy target artifact or enchantment.
• Draw two cards, then discard a card.

Invisible Stalker

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
This creature can't be blocked.

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.)

Master Chef

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

Fight Rigging

Hideaway 5 (When this enchantment enters, 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.

Fertilid

This creature enters with two +1/+1 counters on it.
{1}{G}, Remove a +1/+1 counter from this creature: Target player searches their library for a basic land card, puts it onto the battlefield tapped, then shuffles.

Negate

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.)

Pollenbright Druid

When this creature enters, 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.)

Master Biomancer

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

Plaxcaster Frogling

Graft 3 (This creature enters with three +1/+1 counters on it. Whenever another creature enters, 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.)

Thornwood Falls

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {G} or {U}.

Island

Arcane Signet

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

Terramorphic Expanse

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

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.)

Hapatra, Vizier of Poisons

Whenever Hapatra 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.

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 becomes a copy of target creature with a counter on it, except it's 7/5 and it has this ability.

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.)

Blighted Agent

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
This creature can't be blocked.

Command Tower

Cankerbloom

{1}, Sacrifice this creature: 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.)

Necrogen Rotpriest

Toxic 2 (Players dealt combat damage by this creature also get two poison counters.)
Whenever a creature you control with toxic deals combat damage to a player, that player gets an additional poison counter.
{1}{B}{G}: Target creature you control with toxic gains deathtouch until end of turn.

Swamp

Golgari Signet

Altered Ego

This spell can't be countered.
You may have this creature enter as a copy of any creature on the battlefield, except it enters with X additional +1/+1 counters on it.

Golgari Rot Farm

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {B}{G}.

Dimir Aqueduct

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {U}{B}.

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.)

Exotic Orchard

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

Primal Empathy

At the beginning of your upkeep, draw a card if you control a creature with the greatest power among creatures on the battlefield. Otherwise, put a +1/+1 counter on a creature you control.

Drown in Ichor

Target creature gets -4/-4 until end of turn. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Evolving Wilds

Forest

Plague Stinger

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

Vraska's Fall

Each opponent sacrifices a creature or planeswalker of their choice and gets a poison counter.

Obelisk Spider

Reach
Whenever this creature 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.

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.)

Simic Growth Chamber

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {G}{U}.

Phyresis

Enchant creature
Enchanted creature has infect. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Rampant Growth

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

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.

Nest of Scarabs

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

Cold-Eyed Selkie

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
Whenever this creature deals combat damage to a player, you may draw that many cards.

Flux Channeler

Whenever you cast a noncreature spell, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Scheming Aspirant

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

Infectious Inquiry

You draw two cards and you lose 2 life. Each opponent gets a poison counter.

Temple of Malady

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {B} or {G}.

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.)

Simic Signet

Jiang Yanggu, Wildcrafter

Each creature you control with a +1/+1 counter on it has "{T}: Add one mana of any color."
−1: Put a +1/+1 counter on target creature.

Ezuri, Stalker of Spheres

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

Rogue's Passage

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

Contentious Plan

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

Snakeskin Veil

Put a +1/+1 counter on target creature you control. It gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

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.)

Voidwing Hybrid

Flying
Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
When you proliferate, return this card from your graveyard to your hand.

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.