Mirror Box

The "legend rule" doesn't apply to permanents you control.
Each legendary creature you control gets +1/+1.
Each nontoken creature you control gets +1/+1 for each other creature you control with the same name as that creature.

Roaring Earth

Landfall — Whenever a land you control enters, put a +1/+1 counter on target creature or Vehicle you control.
Channel — {X}{G}{G}, Discard Roaring Earth: Put X +1/+1 counters on target land you control. It becomes a 0/0 green Spirit creature with haste. It's still a land.

Kessig Cagebreakers

Whenever Kessig Cagebreakers attacks, create a 2/2 green Wolf creature token that's tapped and attacking for each creature card in your graveyard.

Belt of Giant Strength

Equipped creature has base power and toughness 10/10.
Equip {10}. This ability costs {X} less to activate, where X is the power of the creature it targets.

Racers' Ring

Racers' Ring enters tapped.
{T}: Add {R} or {G}.
{2}{R}{G}, {T}, Sacrifice Racers' Ring: Draw a card.

Herd Migration

Domain — Create a 3/3 green Beast creature token for each basic land type among lands you control.
{1}{G}, Discard Herd Migration: Search your library for a basic land card, reveal it, put it into your hand, then shuffle. You gain 3 life.

Leyline Invocation

Create a 0/0 green and blue Fractal creature token. Put X +1/+1 counters on it, where X is the number of lands you control.

Band Together

Up to two target creatures you control each deal damage equal to their power to another target creature.

Greater Tanuki

Trample
Channel — {2}{G}, Discard Greater Tanuki: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Colossification

Enchant creature
When Colossification enters, tap enchanted creature.
Enchanted creature gets +20/+20.

Explore the Underdark

Search your library for up to two basic land cards and/or Gate cards, put them onto the battlefield tapped, then shuffle.
You take the initiative.

Storm the Seedcore

Distribute four +1/+1 counters among up to four target creatures you control. Creatures you control gain vigilance and trample until end of turn.

Cinder Glade

({T}: Add {R} or {G}.)
Cinder Glade enters tapped unless you control two or more basic lands.

Fecundity

Whenever a creature dies, that creature's controller may draw a card.

Mossfire Valley

Ivy Lane Denizen

Whenever another green creature you control enters, put a +1/+1 counter on target creature.

Arcane Signet

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

Minsc & Boo, Timeless Heroes

When Minsc & Boo, Timeless Heroes enters and at the beginning of your upkeep, you may create Boo, a legendary 1/1 red Hamster creature token with trample and haste.
+1: Put three +1/+1 counters on up to one target creature with trample or haste.
−2: Sacrifice a creature. When you do, Minsc & Boo, Timeless Heroes deals X damage to any target, where X is that creature's power. If the sacrificed creature was a Hamster, draw X cards.
Minsc & Boo, Timeless Heroes can be your commander.

Urabrask the Hidden

Creatures you control have haste.
Creatures your opponents control enter tapped.

Panic Attack

Up to three target creatures can't block this turn.

Crush of Wurms

Create three 6/6 green Wurm creature tokens.
Flashback {9}{G}{G}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Bristly Bill, Spine Sower

Landfall — Whenever a land you control enters, put a +1/+1 counter on target creature.
{3}{G}{G}: Double the number of +1/+1 counters on each creature you control.

Karplusan Forest

{T}: Add {C}.
{T}: Add {R} or {G}. Karplusan Forest deals 1 damage to you.

Spore Frog

Sacrifice Spore Frog: Prevent all combat damage that would be dealt this turn.

Shatter

Bearer of the Heavens

When Bearer of the Heavens dies, destroy all permanents at the beginning of the next end step.

Favor of Jukai

Enchant artifact or creature
As long as enchanted permanent is a creature, it gets +3/+3 and has reach.
Channel — {1}{G}, Discard Favor of Jukai: Target creature gets +3/+3 and gains reach until end of turn.

Moment's Peace

Prevent all combat damage that would be dealt this turn.
Flashback {2}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Karlach, Fury of Avernus

Whenever you attack, if it's the first combat phase of the turn, untap all attacking creatures. They gain first strike until end of turn. After this phase, there is an additional combat phase.
Choose a Background (You can have a Background as a second commander.)

Copper Host Crusher

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

Wilson, Refined Grizzly

This spell can't be countered.
Vigilance, reach, trample
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
Choose a Background (You can have a Background as a second commander.)

Gaea's Courser

Whenever Gaea's Courser attacks, if there are three or more creature cards in your graveyard, draw a card.

Explosive Entry

Destroy up to one target artifact. Put a +1/+1 counter on up to one target creature.

Vrondiss, Rage of Ancients

Enrage — Whenever Vrondiss, Rage of Ancients is dealt damage, you may create a 5/4 red and green Dragon Spirit creature token with "When this creature deals damage, sacrifice it."
Whenever you roll one or more dice, you may have Vrondiss deal 1 damage to itself.

Elmar, Ulvenwald Informant

Haste
Whenever you cast your second spell each turn, untap target creature, then investigate. (Create a colorless Clue artifact token with "{2}, Sacrifice this artifact: Draw a card.")
Friends forever (You can have two commanders if both have friends forever.)

Molten Influence

Counter target instant or sorcery spell unless its controller has Molten Influence deal 4 damage to them.

Plated Kilnbeast

Menace (This creature can't be blocked except by two or more creatures.)

Bonded Herdbeast

{4}{R/P}: Transform Bonded Herdbeast. Activate only as a sorcery. ({R/P} can be paid with either {R} or 2 life.)

Bonded Herdbeast // Plated Kilnbeast

Stimulus Package

When Stimulus Package enters, create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")
Sacrifice a Treasure: Create a 1/1 green and white Citizen creature token.

Etali, Primal Storm

Whenever Etali, Primal Storm attacks, exile the top card of each player's library, then you may cast any number of spells from among those cards without paying their mana costs.

Staff of the Wild Magus

Whenever you cast a green spell or a Forest you control enters, you gain 1 life.

Putrefax

Trample, haste
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 the end step, sacrifice Putrefax.

Fire Diamond

Fire Diamond enters tapped.
{T}: Add {R}.

Rugged Highlands

Rugged Highlands enters tapped.
When Rugged Highlands enters, you gain 1 life.
{T}: Add {R} or {G}.

Giant Cindermaw

Quirion Beastcaller

Whenever you cast a creature spell, put a +1/+1 counter on Quirion Beastcaller.
When Quirion Beastcaller dies, distribute X +1/+1 counters among any number of target creatures you control, where X is the number of +1/+1 counters on Quirion Beastcaller.

Primal Rage

Creatures you control have trample. (A creature with trample can deal excess combat damage to the player or planeswalker it's attacking.)

Sol Ring

Commander's Sphere

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

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.

Mountain

Game Trail

As Game Trail enters, you may reveal a Mountain or Forest card from your hand. If you don't, Game Trail enters tapped.
{T}: Add {R} or {G}.

Marching Duodrone

Whenever Marching Duodrone attacks, each player creates a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Phylath, World Sculptor

When Phylath, World Sculptor enters, create a 0/1 green Plant creature token for each basic land you control.
Landfall — Whenever a land you control enters, put four +1/+1 counters on target Plant you control.

Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

Sharpshooter Elf

Reach
Sharpshooter Elf's power is equal to the number of creatures you control.
When Sharpshooter Elf enters, it deals damage equal to its power to target creature with flying an opponent controls.

Ironhoof Boar

Trample, haste
Channel — {1}{R}, Discard Ironhoof Boar: Target creature gets +3/+1 and gains trample until end of turn.

Ambitious Dragonborn

Ambitious Dragonborn enters with X +1/+1 counters on it, where X is the greatest power among creatures you control and creature cards in your graveyard.

Moss Diamond

Moss Diamond enters tapped.
{T}: Add {G}.

Stand Together

Put two +1/+1 counters on target creature and two +1/+1 counters on another target creature.

Insurrection

Untap all creatures and gain control of them until end of turn. They gain haste until end of turn.

Whispersilk Cloak

Equipped creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)
Equip {2}

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.

Forest

Hornet Queen

Flying, deathtouch
When Hornet Queen enters, create four 1/1 green Insect creature tokens with flying and deathtouch.

Capricious Hellraiser

This spell costs {3} less to cast if you have nine or more cards in your graveyard.
Flying
When Capricious Hellraiser enters, exile three cards at random from your graveyard. Choose a noncreature, nonland card from among them and copy it. You may cast the copy without paying its mana cost.

Venomous Brutalizer

Toxic 3 (Players dealt combat damage by this creature also get three poison counters.)
When Venomous Brutalizer enters, 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.)

Berserkers' Onslaught

Attacking creatures you control have double strike.

Rampaging Geoderm

Trample, haste
Whenever you attack, target attacking creature gets +1/+1 until end of turn. If it's attacking a battle, put a +1/+1 counter on it instead.

Yorvo, Lord of Garenbrig

Yorvo, Lord of Garenbrig enters with four +1/+1 counters on it.
Whenever another green creature you control enters, put a +1/+1 counter on Yorvo. Then if that creature's power is greater than Yorvo's power, put another +1/+1 counter on Yorvo.

Bookwurm

Trample
When Bookwurm enters, you gain 3 life and draw a card.
{2}{G}: Put Bookwurm from your graveyard into your library third from the top.

Giant Adephage

Trample
Whenever Giant Adephage deals combat damage to a player, create a token that's a copy of Giant Adephage.

Brash Taunter

Indestructible
Whenever Brash Taunter is dealt damage, it deals that much damage to target opponent.
{2}{R}, {T}: Brash Taunter fights another target creature.