Map the Wastes

Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Bolster 1. (Choose a creature with the least toughness among creatures you control and put a +1/+1 counter on it.)

Urban Daggertooth

Vigilance
Enrage — Whenever this creature is dealt damage, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

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.)

Reservoir Walker

When this creature enters, you gain 3 life and get {E}{E}{E} (three energy counters).

Glassblower's Puzzleknot

When this artifact enters, scry 2, then you get {E}{E}. (You get two energy counters. To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)
{2}{U}, Sacrifice this artifact: Scry 2, then you get {E}{E}.

Siren Lookout

Flying
When this creature enters, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)

Aether Herder

When this creature enters, you get {E}{E} (two energy counters).
Whenever this creature attacks, you may pay {E}{E}. If you do, create a 1/1 colorless Servo artifact creature token.

Contentious Plan

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

Highspire Infusion

Target creature gets +3/+3 until end of turn. You get {E}{E} (two energy counters).

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.

Ironshell Beetle

When this creature enters, put a +1/+1 counter on target creature.

Bond Beetle

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.

Gnarlid Colony

Kicker {2}{G} (You may pay an additional {2}{G} as you cast this spell.)
If this creature was kicked, it enters with two +1/+1 counters on it.
Each creature you control with a +1/+1 counter on it has trample. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Courage in Crisis

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.)

Aether Swooper

Flying
When this creature enters, you get {E}{E} (two energy counters).
Whenever this creature attacks, you may pay {E}{E}. If you do, create a 1/1 colorless Servo artifact creature token.

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.)

Sporoloth Ancient

At the beginning of your upkeep, put a spore counter on this creature.
Creatures you control have "Remove two spore counters from this creature: Create a 1/1 green Saproling creature token."

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.

Thriving Rhino

When this creature enters, you get {E}{E} (two energy counters).
Whenever this creature attacks, you may pay {E}{E}. If you do, put a +1/+1 counter on it.

Riparian Tiger

Trample
When this creature enters, you get {E}{E} (two energy counters).
Whenever this creature attacks, you may pay {E}{E}. If you do, it gets +2/+2 until end of turn.

Weapon Rack

This artifact enters with three +1/+1 counters on it.
{T}: Move a +1/+1 counter from this artifact onto target creature. Activate only as a sorcery.

Ior Ruin Expedition

Landfall — Whenever a land you control enters, you may put a quest counter on this enchantment.
Remove three quest counters from this enchantment and sacrifice it: Draw two cards.

Crowned Ceratok

Trample
Each creature you control with a +1/+1 counter on it has trample.

Cystbearer

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

Hightide Hermit

Defender
When this creature enters, you get {E}{E}{E}{E} (four energy counters).
Pay {E}{E}: This creature can attack this turn as though it didn't have defender.

Forge of Heroes

{T}: Add {C}.
{T}: Choose target commander that entered this turn. Put a +1/+1 counter on it if it's a creature and a loyalty counter on it if it's a planeswalker.

Hunt the Weak

Put a +1/+1 counter on target creature you control. Then that creature fights target creature you don't control. (Each deals damage equal to its power to the other.)

Phyrexian Digester

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.)

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 this creature enters, you may return target creature card with infect from your graveyard to your hand.

Sparring Construct

When this creature dies, put a +1/+1 counter on target creature you control.

Thallid Devourer

At the beginning of your upkeep, put a spore counter on this creature.
Remove three spore counters from this creature: Create a 1/1 green Saproling creature token.
Sacrifice a Saproling: This creature gets +1/+2 until end of turn.

Savage Thallid

At the beginning of your upkeep, put a spore counter on this creature.
Remove three spore counters from this creature: Create a 1/1 green Saproling creature token.
Sacrifice a Saproling: Regenerate target Fungus.

Sporeback Troll

Graft 2 (This creature enters with two +1/+1 counters on it. Whenever another creature enters, you may move a +1/+1 counter from this creature onto it.)
{1}{G}: Regenerate target creature with a +1/+1 counter on it.

Attune with Aether

Search your library for a basic land card, reveal it, put it into your hand, then shuffle. You get {E}{E} (two energy counters).

Everflowing Chalice

Multikicker {2} (You may pay an additional {2} any number of times as you cast this spell.)
This artifact enters with a charge counter on it for each time it was kicked.
{T}: Add {C} for each charge counter on this artifact.

Servant of the Scale

This creature enters with a +1/+1 counter on it.
When this creature dies, put X +1/+1 counters on target creature you control, where X is the number of +1/+1 counters on this creature.

Longshot Squad

Outlast {1}{G} ({1}{G}, {T}: Put a +1/+1 counter on this creature. Outlast only as a sorcery.)
Each creature you control with a +1/+1 counter on it has reach. (A creature with reach can block creatures with flying.)

Aetherstream Leopard

Trample
When this creature enters, you get {E} (an energy counter).
Whenever this creature attacks, you may pay {E}. If you do, it gets +2/+0 until end of turn.

Ixalli's Diviner

When this creature enters, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)

Bloom Hulk

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

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.)

Scrounging Bandar

This creature enters with two +1/+1 counters on it.
At the beginning of your upkeep, you may move any number of +1/+1 counters from this creature onto another target creature.

Viridian Betrayers

This creature has infect as long as an opponent is poisoned. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Titanic Brawl

This spell costs {1} less to cast if it targets a creature you control with a +1/+1 counter on it.
Target creature you control fights target creature you don't control. (Each deals damage equal to its power to the other.)

Ainok Survivalist

Megamorph {1}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)
When this creature is turned face up, destroy target artifact or enchantment an opponent controls.

Lifecrafter's Gift

Put a +1/+1 counter on target creature, then put a +1/+1 counter on each creature you control with a +1/+1 counter on it.

Feral Thallid

At the beginning of your upkeep, put a spore counter on this creature.
Remove three spore counters from this creature: Regenerate this creature.

Rogue Refiner

When this creature enters, draw a card and you get {E}{E} (two energy counters).

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.

Opal Palace

{T}: Add {C}.
{1}, {T}: Add one mana of any color in your commander's color identity. If you spend this mana to cast your commander, it enters with a number of additional +1/+1 counters on it equal to the number of times it's been cast from the command zone this game.

Kiora's Dambreaker

Thorn Thallid

At the beginning of your upkeep, put a spore counter on this creature.
Remove three spore counters from this creature: It deals 1 damage to any target.

Ainok Guide

When this creature enters, choose one —
• Put a +1/+1 counter on this creature.
• Search your library for a basic land card, reveal it, then shuffle and put that card on top.

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.)

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.)

Thallid

At the beginning of your upkeep, put a spore counter on this creature.
Remove three spore counters from this creature: Create a 1/1 green Saproling creature token.

Steady Progress

Forest

Thriving Turtle

Shipwreck Moray

When this creature enters, you get {E}{E}{E}{E} (four energy counters).
Pay {E}: This creature gets +2/-2 until end of turn.

Marsh Viper

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

Sphere of the Suns

This artifact enters tapped and with three charge counters on it.
{T}, Remove a charge counter from this artifact: Add one mana of any color.

Aven Eternal

Flying
When this creature enters, amass Zombies 1. (Put a +1/+1 counter on an Army you control. It's also a Zombie. If you don't control an Army, create a 0/0 black Zombie Army creature token first.)

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.

Scale the Heights

Put a +1/+1 counter on up to one target creature. You gain 2 life. You may play an additional land this turn.
Draw a card.

Woodweaver's Puzzleknot

When this artifact enters, you gain 3 life and get {E}{E}{E} (three energy counters).
{2}{G}, Sacrifice this artifact: You gain 3 life and get {E}{E}{E}.

Chained Throatseeker

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 attack unless defending player is poisoned.

Duskshell Crawler

When this creature enters, put a +1/+1 counter on target creature.
Each creature you control with a +1/+1 counter on it has trample. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Ichorclaw Myr

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Whenever this creature becomes blocked, it gets +2/+2 until end of turn.

Rot Wolf

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Whenever a creature dealt damage by Rot Wolf this turn dies, you may draw a card.

Sage of Shaila's Claim

When this creature enters, you get {E}{E}{E} (three energy counters).

Virulent Sliver

All Sliver creatures have poisonous 1. (Whenever a Sliver deals combat damage to a player, that player gets a poison counter. A player with ten or more poison counters loses the game.)

Guildpact Informant

Flying
Whenever this creature deals combat damage to a player or planeswalker, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Aether Theorist

When this creature enters, you get {E}{E}{E} (three energy counters).
{T}, Pay {E}: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Pridemalkin

When this creature enters, put a +1/+1 counter on target creature you control.
Each creature you control with a +1/+1 counter on it has trample. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Tishana's Wayfinder

Island

Glistener Elf

Sabertooth Cobra

Whenever this creature deals damage to a player, that player gets a poison counter. The player gets another poison counter at the beginning of their next upkeep unless they pay {2} before that step. (A player with ten or more poison counters loses the game.)

Teferi's Time Twist

Exile target permanent you control. Return that card to the battlefield under its owner's control at the beginning of the next end step. If it enters as a creature, it enters with an additional +1/+1 counter on it.

Satyr Grovedancer

Callous Dismissal

Return target nonland permanent to its owner's hand.
Amass Zombies 1. (Put a +1/+1 counter on an Army you control. It's also a Zombie. If you don't control an Army, create a 0/0 black Zombie Army creature token first.)

Khalni Heart Expedition

Landfall — Whenever a land you control enters, you may put a quest counter on this enchantment.
Remove three quest counters from this enchantment and sacrifice it: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Tel-Jilad Fallen

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

Outmuscle

Put a +1/+1 counter on target creature you control, then it fights target creature you don't control. (Each deals damage equal to its power to the other.)
Adamant — If at least three green mana was spent to cast this spell, the creature you control gains indestructible until end of turn.

Pistus Strike

Destroy target creature with flying. Its controller gets a poison counter.

Consulate Turret

{T}: You get {E} (an energy counter).
{T}, Pay {E}{E}{E}: This artifact deals 2 damage to target player or planeswalker.

Soul's Might

Put X +1/+1 counters on target creature, where X is that creature's power.

Cloudfin Raptor

Flying
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.)

Thallid Germinator

At the beginning of your upkeep, put a spore counter on this creature.
Remove three spore counters from this creature: Create a 1/1 green Saproling creature token.
Sacrifice a Saproling: Target creature gets +1/+1 until end of turn.

Thallid Shell-Dweller

Defender
At the beginning of your upkeep, put a spore counter on this creature.
Remove three spore counters from this creature: Create a 1/1 green Saproling creature token.

Vitaspore Thallid

At the beginning of your upkeep, put a spore counter on this creature.
Remove three spore counters from this creature: Create a 1/1 green Saproling creature token.
Sacrifice a Saproling: Target creature gains haste until end of turn.