Adaptive Sporesinger

Vigilance
When Adaptive Sporesinger enters, choose one —
• Target creature gets +2/+2 and gains vigilance until end of turn.
• Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Adarkar Wastes

{T}: Add {C}.
{T}: Add {W} or {U}. Adarkar Wastes deals 1 damage to you.

Blossoming Sands

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

Quicksilver Servitor

Ward {2}
Whenever you cast a spell from among cards put into your hand this turn, proliferate.

Thornwood Falls

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

Swamp

Contagious Vorrac

When Contagious Vorrac enters, look at the top four cards of your library. You may reveal a land card from among them and put it into your hand. Put the rest on the bottom of your library in a random order. If you didn't put a card into your hand this way, 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.

Gyox, Brutal Carnivora

At the beginning of your end step, put an oil counter on up to one target creature.
Whenever a nontoken creature you control with one or more oil counters on it dies, conjure X duplicates of it into exile, where X is the number of oil counters on it. Those duplicates perpetually get +X/+X. Then shuffle those duplicates into your library.

Vexyr, Ich-Tekik's Heir

Whenever you seek one or more cards, create a 3/3 colorless Phyrexian Golem artifact creature token.
Golems you control have vigilance.

Crawling Chorus

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
When Crawling Chorus dies, create a 1/1 colorless Phyrexian Mite artifact creature token with toxic 1 and "This creature can't block."

Feast of the Victorious Dead

At the beginning of your end step, if one or more creatures died this turn, you gain that much life and distribute that many +1/+1 counters among creatures you control.

Jungle Hollow

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

Mephidross Slime

Trample
When Mephidross Slime dies, conjure a card named Mephidross Slime into your graveyard. Perpetually double the power and toughness of Mephidross Slime and that card, then shuffle them into their owner's library.

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.)

Compleat Devotion

Target creature you control gets +2/+2 until end of turn. If that creature has toxic, draw a card.

Flensing Raptor

Flying
Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
When Flensing Raptor enters, another target creature you control with toxic gets +1/+1 and gains flying until end of turn.

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.)

Seething Skitter-Priest

Toxic 1
When Seething Skitter-Priest enters, creatures you control and creature cards in your hand perpetually gain "When this creature dies, create a 1/1 colorless Phyrexian Mite artifact creature token with toxic 1 and 'This creature can't block.'"

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.)

Plains

Ichor Aberration

Flying, Defender
As long as Ichor Aberration's power is 7 or greater, it can attack as though it didn't have defender.
Whenever you proliferate, if Ichor Aberration is in your graveyard or on the battlefield, Ichor Aberration perpetually gets +1/+1. You may cast it from your graveyard this turn.

Skullpiercer Gnat

Flying
Toxic 1
Whenever Skullpiercer Gnat deals combat damage to a player, a random nonland card in that player's hand perpetually gains "When you cast this spell, you get a poison counter."

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.)

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.)

Assemble the Team

Search the top third of your library, rounded up, for a card. Put that card into your hand, then shuffle.

Evolving Wilds

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