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.)

Deathsprout

Destroy target creature. Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Swamp

Prosthetic Injector

Equipped creature gets +0/+2 and has toxic 1. (Players dealt combat damage by equipped creature also get a poison counter.)
Equip {1}

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.

Sol Ring

Pestilent Syphoner

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

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.)

Have

Ram Through

Target creature you control deals damage equal to its power to target creature you don't control. If the creature you control has trample, excess damage is dealt to that creature's controller instead.

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.)

Forest

Dictate of Karametra

Flash
Whenever a player taps a land for mana, that player adds one mana of any type that land produced.

Collective Voyage

Join forces — Starting with you, each player may pay any amount of mana. Each player searches their library for up to X basic land cards, where X is the total amount of mana paid this way, puts them onto the battlefield tapped, then shuffles.

Kaervek the Merciless

Whenever an opponent casts a spell, Kaervek the Merciless deals damage equal to that spell's mana value to any target.

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.)

Ichorspit Basilisk

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

Corpse Cur

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
When Corpse Cur enters, you may return target creature card with infect from your graveyard to your hand.

Grafted Exoskeleton

Equipped creature gets +2/+2 and has infect. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Whenever Grafted Exoskeleton becomes unattached from a permanent, sacrifice that permanent.
Equip {2}

City on Fire

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 a source you control would deal damage to a permanent or player, it deals triple that damage instead.

Whisper of the Dross

Target creature gets -1/-1 until end of turn. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Karn's Bastion

{T}: Add {C}.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Return to Nature

Choose one —
• Destroy target artifact.
• Destroy target enchantment.
• Exile target card from a graveyard.

Blightwidow

Reach (This creature can block creatures with flying.)
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Yurlok of Scorch Thrash

Vigilance
A player losing unspent mana causes that player to lose that much life.
{1}, {T}: Each player adds {B}{R}{G}.

Tail Swipe

Choose target creature you control and target creature you don't control. If you cast this spell during your main phase, the creature you control gets +1/+1 until end of turn. Then those creatures fight each other. (Each deals damage equal to its power to the other.)

Tyrranax Atrocity

Haste
Toxic 3 (Players dealt combat damage by this creature also get three poison counters.)

Sheoldred's Headcleaver

Menace
Toxic 2 (Players dealt combat damage by this creature also get two poison counters.)

Spread the Sickness

Destroy target creature, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Beast Within

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

Mountain

Overabundance

Whenever a player taps a land for mana, that player adds one mana of any type that land produced, and Overabundance deals 1 damage to the player.

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.

Horizon Stone

If you would lose unspent mana, that mana becomes colorless instead.

Soul's Fire

Target creature you control deals damage equal to its power to any target.

Rampant Growth

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

Harrow

As an additional cost to cast this spell, sacrifice a land.
Search your library for up to two basic land cards, put them onto the battlefield, then shuffle.

Swiftfoot Boots

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

Rites of Flourishing

At the beginning of each player's draw step, that player draws an additional card.
Each player may play an additional land on each of their turns.

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

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.

Necrogen Communion

Enchant creature you control
Enchanted creature has toxic 2. (Players dealt combat damage by it also get two poison counters.)
When enchanted creature dies, return that card to the battlefield under your control.

Fynn, the Fangbearer

Deathtouch
Whenever a creature you control with deathtouch deals combat damage to a player, that player gets two poison counters. (A player with ten or more poison counters loses the game.)

Etali, Primal Sickness

Trample, indestructible
Whenever Etali, Primal Sickness deals combat damage to a player, they get that many poison counters. (A player with ten or more poison counters loses the game.)

Etali, Primal Conqueror

Trample
When Etali, Primal Conqueror enters, each player exiles cards from the top of their library until they exile a nonland card. You may cast any number of spells from among the nonland cards exiled this way without paying their mana costs.
{9}{G/P}: Transform Etali. Activate only as a sorcery.

Etali, Primal Conqueror // Etali, Primal Sickness

Saryth, the Viper's Fang

Other tapped creatures you control have deathtouch.
Other untapped creatures you control have hexproof.
{1}, {T}: Untap another target creature or land you control.

Noxious Assault

Creatures you control get +2/+2 until end of turn. Whenever a creature blocks this turn, its controller gets a poison counter.

Hazardous Blast

Hazardous Blast deals 1 damage to each creature your opponents control. Creatures your opponents control can't block this turn.

Goblin Anarchomancer

Each spell you cast that's red or green costs {1} less to cast.

Solphim, Mayhem Dominus

If a source you control would deal noncombat damage to an opponent or a permanent an opponent controls, it deals double that damage to that player or permanent instead.
{1}{R/P}{R/P}, Discard two cards: Put an indestructible counter on Solphim, Mayhem Dominus. ({R/P} can be paid with either {R} or 2 life.)

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.

Plague Myr

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

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.)

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.)

Electrodominance

Electrodominance deals X damage to any target. You may cast a spell with mana value X or less from your hand without paying its mana cost.

Phyrexian Swarmlord

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
At the beginning of your upkeep, create a 1/1 green Phyrexian Insect creature token with infect for each poison counter your opponents have.

Bojuka Bog

Bojuka Bog enters tapped.
When Bojuka Bog enters, exile target player's graveyard.
{T}: Add {B}.

Gulping Scraptrap

When Gulping Scraptrap enters or dies, 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.

Rootweaver Druid

When Rootweaver Druid enters, each opponent may search their library for up to three basic land cards. They each put one of those cards onto the battlefield tapped under your control and the rest onto the battlefield tapped under their control. Then each player who searched their library this way shuffles.

Anoint with Affliction

Exile target creature if it has mana value 3 or less.
Corrupted — Exile that creature instead if its controller has three or more poison counters.

Casualties of War

Choose one or more —
• Destroy target artifact.
• Destroy target creature.
• Destroy target enchantment.
• Destroy target land.
• Destroy target planeswalker.

Ichor Rats

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
When Ichor Rats enters, each player gets a poison counter.

Tyvar's Stand

Target creature you control gets +X/+X and gains hexproof and indestructible until end of turn. (A creature with hexproof and indestructible can't be the target of spells or abilities your opponents control. Damage and effects that say "destroy" don't destroy it.)

Llanowar Elves

Power Surge

At the beginning of each player's upkeep, Power Surge deals X damage to that player, where X is the number of untapped lands they controlled at the beginning of this turn.

Park Heights Maverick

Dethrone (Whenever this creature attacks the player with the most life or tied for the most life, put a +1/+1 counter on it.)
Park Heights Maverick can't be blocked by creatures with power 2 or less.
Whenever Park Heights Maverick deals combat damage to a player or dies, proliferate.

Terminate

Destroy target creature. It can't be regenerated.

Heartbeat of Spring

Whenever a player taps a land for mana, that player adds one mana of any type that land produced.