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.)

Plains

Paladin of Predation

Toxic 6 (Players dealt combat damage by this creature also get six poison counters.)
Paladin of Predation can't be blocked by creatures with power 2 or less.

Contaminant Grafter

Trample, toxic 1
Whenever one or more creatures you control deal combat damage to one or more players, proliferate.
Corrupted — At the beginning of your end step, if an opponent has three or more poison counters, draw a card, then you may put a land card from your hand onto the battlefield.

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.)

Brimaz, Blight of Oreskos

Whenever you cast a Phyrexian creature or artifact creature spell, incubate X, where X is that spell's mana value. (Create an Incubator token with X +1/+1 counters on it and "{2}: Transform this artifact." It transforms into a 0/0 Phyrexian artifact creature.)
At the beginning of each end step, if a Phyrexian died under your control this turn, proliferate.

Carnivorous Canopy

Destroy target artifact, enchantment, or creature with flying. If that permanent's mana value was 3 or less, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Dimir Signet

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.

Opulent Palace

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

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.)

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Phyrexian Awakening

When Phyrexian Awakening enters the battlefield, incubate 4. (Create an Incubator token with four +1/+1 counters on it and "{2}: Transform this artifact." It transforms into a 0/0 Phyrexian artifact creature.)
Phyrexians you control have vigilance.

Ezuri, Stalker of Spheres

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

Go for the Throat

Tyrranax Rex

This spell can't be countered.
Trample, ward {4}, haste
Toxic 4 (Players dealt combat damage by this creature also get four poison counters.)

Slaughter Singer

Toxic 2 (Players dealt combat damage by this creature also get two poison counters.)
Whenever another creature you control with toxic attacks, it gets +1/+1 until end of turn.

Sandsteppe Citadel

Sandsteppe Citadel enters the battlefield tapped.
{T}: Add {W}, {B}, or {G}.

Vat Emergence

Put target creature card from a graveyard onto the battlefield under your control. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Azorius Signet

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Armored Scrapgorger

Armored Scrapgorger gets +3/+0 as long as it has three or more oil counters on it.
{T}: Add one mana of any color.
Whenever Armored Scrapgorger becomes tapped, exile target card from a graveyard and put an oil counter on Armored Scrapgorger.

White Sun's Twilight

You gain X life. Create X 1/1 colorless Phyrexian Mite artifact creature tokens with toxic 1 and "This creature can't block." If X is 5 or more, destroy all other creatures. (Players dealt combat damage by a creature with toxic 1 also get a poison counter.)

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Bloated Contaminator

Trample
Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
Whenever Bloated Contaminator 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.)

Sol Ring

Seaside Citadel

Seaside Citadel enters the battlefield tapped.
{T}: Add {G}, {W}, or {U}.

Vat of Rebirth

Whenever another artifact or creature you control is put into a graveyard from the battlefield, put an oil counter on Vat of Rebirth.
{2}{B}, {T}, Remove four oil counters from Vat of Rebirth: Return target creature card from your graveyard to the battlefield. Activate only as a sorcery.

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.

Lotus Blossom

At the beginning of your upkeep, you may put a petal counter on Lotus Blossom.
{T}, Sacrifice Lotus Blossom: Add X mana of any one color, where X is the number of petal counters on Lotus Blossom.

Unclaimed Territory

As Unclaimed Territory enters the battlefield, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type.

Golgari Signet

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Temple of the False God

{T}: Add {C}{C}. Activate only if you control five or more lands.

Island

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.

Forest

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.)

Infectious Inquiry

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

Wrath of God

Destroy all creatures. They can't be regenerated.

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.)

The Seedcore

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast Phyrexian creature spells.
Corrupted — {T}: Target 1/1 creature gets +2/+1 until end of turn. Activate only if an opponent has three or more poison counters.

Ixhel, Scion of Atraxa

Flying, vigilance, toxic 2
Corrupted — At the beginning of your end step, each opponent who has three or more poison counters exiles the top card of their library face down. You may look at and play those cards for as long as they remain exiled, and you may spend mana as though it were mana of any color to cast those spells.

Glissa, Herald of Predation

At the beginning of combat on your turn, choose one —
• Incubate 2 twice. (To incubate 2, create an Incubator token with two +1/+1 counters on it and "{2}: Transform this artifact." It transforms into a 0/0 Phyrexian artifact creature.)
• Transform all Incubator tokens you control.
• Phyrexians you control gain first strike and deathtouch until end of turn.

Venerated Rotpriest

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
Whenever a creature you control becomes the target of a spell, target opponent gets a poison counter.

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.)

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.)

Tainted Observer

Flying
Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
Whenever another creature enters the battlefield under your control, 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.)

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.)

Damnation

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Serum Snare

Return target nonland permanent to its owner's hand. If that permanent had mana value 3 or less, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Reliquary Tower

Reject Imperfection

Counter target spell. If that spell's mana value was 3 or less, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Atraxa, Praetors' Voice

Flying, vigilance, deathtouch, lifelink
At the beginning of your end step, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Command Tower

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

Phyrexian Arena

At the beginning of your upkeep, you draw a card and you lose 1 life.

Sunfall

Exile all creatures. Incubate X, where X is the number of creatures exiled this way. (Create an Incubator token with X +1/+1 counters on it and "{2}: Transform this artifact." It transforms into a 0/0 Phyrexian artifact creature.)

Voidwing Hybrid

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

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.

Arcane Signet

Phyresis Outbreak

Each opponent gets a poison counter. Then each creature your opponents control gets -1/-1 until end of turn for each poison counter its controller has.

Glissa Sunslayer

First strike, deathtouch
Whenever Glissa Sunslayer deals combat damage to a player, choose one —
• You draw a card and you lose 1 life.
• Destroy target enchantment.
• Remove up to three counters from target permanent.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Tekuthal, Inquiry Dominus

Flying
If you would proliferate, proliferate twice instead.
{1}{U/P}{U/P}, Remove three counters from among other artifacts, creatures, and planeswalkers you control: Put an indestructible counter on Tekuthal, Inquiry Dominus. ({U/P} can be paid with either {U} or 2 life.)

Progenitor Exarch

When Progenitor Exarch enters the battlefield, incubate 3 X times. (To incubate 3, create an Incubator token with three +1/+1 counters on it and "{2}: Transform this artifact." It transforms into a 0/0 Phyrexian artifact creature.)
{T}: Transform target Incubator token you control.

Infernal Grasp

Destroy target creature. You lose 2 life.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

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.)

Prologue to Phyresis

Each opponent gets a poison counter.
Draw a card.

Vishgraz, the Doomhive

Menace, toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
When Vishgraz, the Doomhive enters the battlefield, create three 1/1 colorless Phyrexian Mite artifact creature tokens with toxic 1 and "This creature can't block."
Vishgraz gets +1/+1 for each poison counter your opponents have.

Venomous Brutalizer

Toxic 3 (Players dealt combat damage by this creature also get three poison counters.)
When Venomous Brutalizer enters the battlefield, you may pay {1}{G}. If you do, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Staff of Compleation

{T}, Pay 1 life: Destroy target permanent you own.
{T}, Pay 2 life: Add one mana of any color.
{T}, Pay 3 life: Proliferate.
{T}, Pay 4 life: Draw a card.
{5}: Untap Staff of Compleation.

Exotic Orchard

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

Vraska's Fall

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

Ertai Resurrected

Flash
When Ertai Resurrected enters the battlefield, choose up to one —
• Counter target spell, activated ability, or triggered ability. Its controller draws a card.
• Destroy another target creature or planeswalker. Its controller draws a card.