Undergrowth Stadium

This land enters tapped unless you have two or more opponents.
{T}: Add {B} or {G}.

Mikey & Mona, Mutant Sitters

When Mikey & Mona enter, choose one or both. Each mode must target a different player.
• Target player chooses a creature they control and puts two +1/+1 counters on it.
• Target player returns a creature or land card from their graveyard to their hand.

Mighty Mutanimals

When this creature enters, create a 2/2 red Mutant creature token.
Alliance — Whenever another creature you control enters, put a +1/+1 counter on target creature you control.

Shared Roots

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

Donatello, Rad Scientist

Vigilance (Attacking doesn't cause this creature to tap.)
When Donatello enters, tap up to three target creatures your opponents control. Put a stun counter on each of them. (If a permanent with a stun counter would become untapped, remove one from it instead.)

Containment Protocol

Enchant creature
When this Aura enters, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Boomerang Basics

Return target nonland permanent to its owner's hand. If you controlled that permanent, draw a card.

Irma, Part-Time Mutant

At the beginning of combat on your turn, Irma becomes a copy of up to one other target creature you control, except her name is Irma, Part-Time Mutant and she has this ability. Then put a +1/+1 counter on her.

Command Tower

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

East Wind Avatar

Flying, vigilance
Alliance — Whenever another creature you control enters, this creature gets +1/+0 until end of turn.

Octopus Form

Target creature you control gets +1/+1 and gains hexproof until end of turn. Untap it. (It can't be the target of spells or abilities your opponents control.)

Utrom Scientists

When this creature enters, tap up to one target creature and put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)

Raph's Bravado

During your turn, attacking creatures get +1/+0.

Swamp

Spark Double

You may have this creature enter as a copy of a creature or planeswalker you control, except it enters with an additional +1/+1 counter on it if it's a creature, it enters with an additional loyalty counter on it if it's a planeswalker, and it isn't legendary.

Devoted Druid

{T}: Add {G}.
Put a -1/-1 counter on this creature: Untap this creature.

Utrom Monitor

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Flying (This creature can't be blocked except by creatures with flying or reach.)

Saved by the Shell

This spell costs {1} less to cast if you control a Turtle.
Put a +1/+1 counter on target creature you control. It gains trample, hexproof, and indestructible until end of turn.

Mouser Attack!

Choose one —
• Create a 1/1 colorless Robot artifact creature token.
• Target creature gets +3/+0 and gains first strike until end of turn.

Tranquil Domain

Vanquish the Horde

This spell costs {1} less to cast for each creature on the battlefield.
Destroy all creatures.

Crustacean Commando

When this creature enters, create a Mutagen token. (It's an artifact with "{1}, {T}, Sacrifice this token: Put a +1/+1 counter on target creature. Activate only as a sorcery.")

Ninja Pizza

Foods you control have "{T}, Sacrifice this artifact: Add one mana of any color."
At the beginning of your second main phase, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")

Novel Nunchaku

When this Equipment enters, attach it to target creature you control. When you do, equipped creature fights up to one target creature an opponent controls. (Each deals damage equal to its power to the other.)
Equipped creature gets +1/+1 and has trample.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Bebop, Skull & Crossbones

Partner with Rocksteady, Mutant Marauder (When this creature enters, target player may put Rocksteady into their hand from their library, then shuffle.)
Deathtouch
Whenever Bebop deals combat damage to a player, you may draw X cards, where X is the number of counters on Bebop. If you do, you lose X life.

Continue?

Choose up to four target creature cards in your graveyard that were put there from the battlefield this turn. Return them to the battlefield.

Accumulate Wisdom

Look at the top three cards of your library. Put one of those cards into your hand and the rest on the bottom of your library in any order. Put each of those cards into your hand instead if there are three or more Lesson cards in your graveyard.

Young Pyromancer

Whenever you cast an instant or sorcery spell, create a 1/1 red Elemental creature token.

Foe-liage

Whenever a land enters during your turn, put a +1/+1 counter on this creature.

Coin of Mastery

Each creature you control enters with an additional +1/+1 counter on it for each mana from an artifact source spent to cast it.
{T}: Create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Season of Growth

Whenever a creature you control enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Whenever you cast a spell that targets a creature you control, draw a card.

Mona Lisa, Ever Adaptable

Whenever a player casts a creature spell, you create a Mutagen token. (It's an artifact with "{1}, {T}, Sacrifice this token: Put a +1/+1 counter on target creature. Activate only as a sorcery.")

Shellshock

For each opponent, choose up to one target creature that player controls. Shellshock deals X damage to each of those creatures. You create a Mutagen token for each creature dealt damage this way. (They're artifacts with "{1}, {T}, Sacrifice this token: Put a +1/+1 counter on target creature. Activate only as a sorcery.")

Donatello, Turtle Techie

When Donatello enters, if you control an artifact, draw a card.

Sodden Verdure

({T}: Add {G} or {U}.)
This land enters tapped unless you control two or more basic lands.

Rocksteady, Mutant Marauder

Partner with Bebop, Skull & Crossbones (When this creature enters, target player may put Bebop into their hand from their library, then shuffle.)
Trample
Whenever another nontoken creature you control enters, put a +1/+1 counter on target creature.

Raphael, the Muscle

Double all damage that creatures you control with counters on them would deal.
When Raphael enters, create a Mutagen token.
Partner—Character select (You can have two commanders if both have this ability.)

Negate

Path of Ancestry

This land enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Dragonskull Summit

This land enters tapped unless you control a Swamp or a Mountain.
{T}: Add {B} or {R}.

Hamato Guardian Stance

Target creature gets +1/+3 and gains flying until end of turn. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Donatello, Way with Machines

Flying
Whenever an artifact you control enters, put a +1/+1 counter on Donatello.

Consider

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Draw a card.

Henchbots

When this creature enters, exile target tapped creature an opponent controls until this creature leaves the battlefield.

Michelangelo, Game Master

Disappear — At the beginning of your end step, if a permanent left the battlefield under your control this turn, put a +1/+1 counter on Michelangelo.

Ray Fillet, Wave Warrior

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.)
Whenever a creature you control with a counter on it deals combat damage to a player, draw a card.

Evolving Wilds

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

Counterspell

Ponder

Look at the top three cards of your library, then put them back in any order. You may shuffle.
Draw a card.

April O'Neil, Human Element

Whenever a player casts an artifact, instant, or sorcery spell, you create a Mutagen token. (It's an artifact with "{1}, {T}, Sacrifice this token: Put a +1/+1 counter on target creature. Activate only as a sorcery.")

Slithering Cryptid

General Traag, Heart of Stone

Trample
When General Traag enters, you may sacrifice another artifact. When you do, General Traag deals 4 damage to target creature.

Casey Jones, Asphalt Hooligan

Double strike (This creature deals both first-strike and regular combat damage.)
{4}: Double Casey Jones's power until end of turn. Any player may activate this ability.

Tempestra, Dame of Games

{2}{R}, {T}, Sacrifice an artifact: Create a token that's a copy of another target creature you control, except it isn't legendary. It gains haste. Sacrifice it at the beginning of the next end step.

Make Your Move

Destroy target artifact, enchantment, or creature with power 4 or greater.

High Score

If one or more +1/+1 counters would be put on a creature you control, that many plus one +1/+1 counters are put on it instead.
At the beginning of your end step, draw a card if you control a creature with the greatest power among creatures on the battlefield.

Ticked Off

Target creature gains double strike until end of turn. (It deals both first-strike and regular combat damage.)

Overwhelming Victory

Overwhelming Victory deals 5 damage to target creature. Each creature you control gains trample and gets +X/+0 until end of turn, where X is the amount of excess damage dealt this way.

Wall of Lost Thoughts

Defender (This creature can't attack.)
When this creature enters, target player mills four cards. (They put the top four cards of their library into their graveyard.)

Primordial Pachyderm

Reach, trample
When this creature enters, you gain 2 life.

Guttersnipe

Whenever you cast an instant or sorcery spell, this creature deals 2 damage to each opponent.

Basic Conjuration

Look at the top six cards of your library. You may reveal a creature card from among them and put it into your hand. Put the rest on the bottom of your library in a random order. You gain 3 life.

Mouser Mark III

This creature can't attack unless you control another artifact.

Krang, the All-Powerful

If a player drawing a card causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
Whenever a player draws their second card each turn, put a +1/+1 counter on Krang.

Mind Transfer Protocol

Until end of turn, target artifact or creature becomes an artifact creature with base power and toughness 4/5.
Draw a card.

Iroh, Grand Lotus

Firebending 2
During your turn, each non-Lesson instant and sorcery card in your graveyard has flashback. The flashback cost is equal to that card's mana cost. (You may cast a card from your graveyard for its flashback cost. Then exile it.)
During your turn, each Lesson card in your graveyard has flashback {1}.

Frog Butler

Deathtouch
{T}: Add one mana of any color.
{2}: This creature gains reach until end of turn.

Aang's Journey

Kicker {2} (You may pay an additional {2} as you cast this spell.)
Search your library for a basic land card. If this spell was kicked, instead search your library for a basic land card and a Shrine card. Reveal those cards, put them into your hand, then shuffle.
You gain 2 life.

Casey Jones, Jury-Rig Justiciar

Haste
When Casey Jones enters, look at the top four cards of your library. You may reveal an artifact card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Thriving Grove

This land enters tapped. As it enters, choose a color other than green.
{T}: Add {G} or one mana of the chosen color.

Ray Fillet, Man Ray

Flying
When Ray Fillet enters, create a Mutagen token. (It's an artifact with "{1}, {T}, Sacrifice this token: Put a +1/+1 counter on target creature. Activate only as a sorcery.")
{2}, Remove a +1/+1 counter from a creature you control: Draw a card.

Sol Ring

Island

Containment Breach

Destroy target artifact or enchantment. If its mana value is 2 or less, create a 1/1 black and green Pest creature token with "When this token dies, you gain 1 life."

Raphael, Tough Turtle

Alliance — Whenever another creature you control enters, Raphael deals 1 damage to target opponent.

Shredder, Shadow Master

Whenever Shredder attacks a player, for each other opponent, create a token that's a copy of Shredder tapped and attacking that player, except it isn't legendary. Sacrifice those tokens at end of combat.
Whenever Shredder deals combat damage to a player, that player loses half their life, rounded up.

Tenderize

Target creature you control deals damage equal to its power to target creature an opponent controls.

Harmonize

Introduction to Prophecy

Geistwave

Hamato Ninpō

Hamato Ninpō deals 4 damage to target attacking or blocking creature.

Rain-Slicked Copse

({T}: Add {G} or {U}.)
This land enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Swift Demise

Swift Demise deals 1 damage to target creature. Then destroy each creature you don't control that was dealt damage this turn.

Mona Lisa, Science Geek

Reach
{T}: Add X mana of any one color, where X is Mona Lisa's power.

Tam, Mindful First-Year

Each other creature you control has hexproof from each of its colors.
{T}: Target creature you control becomes all colors until end of turn.

Leonardo, the Balance

Whenever a token you control enters, you may put a +1/+1 counter on each creature you control. Do this only once each turn.
{W}{U}{B}{R}{G}: Creatures you control gain menace, trample, and lifelink until end of turn.
Partner—Character select (You can have two commanders if both have this ability.)

Featherbrained Filcher

Flying
When this creature leaves the battlefield, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")

Sewer-veillance Cam

Flash
When this artifact enters or leaves the battlefield, you may tap or untap target creature.
{3}{U}, Sacrifice this artifact: Draw two cards.

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.

Guac & Marshmallow Pizza

Flash
When this artifact enters, target creature gets +2/+2 until end of turn. Untap it.
{2}, {T}, Sacrifice this artifact: You gain 3 life.

Gift of the Viper

Put a +1/+1 counter, a reach counter, and a deathtouch counter on target creature. Untap it.

Rat King, Pale Piper

Menace
Whenever Rat King or another nontoken creature you control leaves the battlefield, create a 1/1 black Rat creature token.
{2}, Sacrifice a token: Draw a card.

Spider-Sense

Web-slinging {U} (You may cast this spell for {U} if you also return a tapped creature you control to its owner's hand.)
Counter target instant spell, sorcery spell, or triggered ability.

How to Start a Riot

Target creature gains menace until end of turn. (It can't be blocked except by two or more creatures.)
Creatures target player controls get +2/+0 until end of turn.

Triceraton Regenta

Vigilance (Attacking doesn't cause this creature to tap.)
Whenever this creature attacks, untap up to one other target creature.

Hullbreaker Horror

Flash
This spell can't be countered.
Whenever you cast a spell, choose up to one —
• Return target spell you don't control to its owner's hand.
• Return target nonland permanent to its owner's hand.

Spicy Oatmeal Pizza

When this artifact enters, it deals 4 damage to any target and 3 damage to you.
{2}, {T}, Sacrifice this artifact: You gain 3 life.

Bender's Waterskin

Untap this artifact during each other player's untap step.
{T}: Add one mana of any color.

Raphael, Most Attitude

Menace (This creature can't be blocked except by two or more creatures.)
Alliance — Whenever another creature you control enters, you may exile the top card of your library.
Whenever Raphael attacks, until end of turn, you may play a card exiled with Raphael.

Biogenic Ooze

When this creature enters, create a 2/2 green Ooze creature token.
At the beginning of your end step, put a +1/+1 counter on each Ooze you control.
{1}{G}{G}{G}: Create a 2/2 green Ooze creature token.

Mirror of the Forebears

As this artifact enters, choose a creature type.
{1}: Until end of turn, this artifact becomes a copy of target creature you control of the chosen type, except it's an artifact in addition to its other types.

Quintessential Katana

Equipped creature gets +1/+1 and has "Whenever this creature deals combat damage, untap it and you gain 2 life."
Whenever a Ninja you control enters, you may attach this Equipment to it.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Origin of Metalbending

Choose one —
• Destroy target artifact or enchantment.
• Put a +1/+1 counter on target creature you control. It gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Burning Vengeance

Whenever you cast a spell from your graveyard, this enchantment deals 2 damage to any target.

Hidden Hideout

This land enters tapped.
{T}: Add one mana of any color in your commander's color identity.
{2}, {T}: Target creature you control with a counter on it gains lifelink until end of turn.