Grounded for Life

This spell costs {3} less to cast if it targets a tapped creature.
Destroy target creature.

Shark Shredder, Killer Clone

Sneak {3}{B}{B}
First strike
Whenever Shark Shredder deals combat damage to a player, put up to one target creature card from that player's graveyard onto the battlefield under your control. It enters tapped and attacking that player.

Leatherhead, Swamp Stalker

Trample
Leatherhead enters with a hexproof counter on her.
Whenever Leatherhead deals combat damage to a player, you may remove a counter from her. When you do, destroy target artifact or enchantment that player controls.

Splinter, Hamato Yoshi

Sneak {B} (You may cast this spell for {B} if you also return an unblocked attacker you control to hand during the declare blockers step. He enters tapped and attacking.)
Menace (This creature can't be blocked except by two or more creatures.)
Other Ninjas you control get +1/+1.

Leonardo, Worldly Warrior

This spell costs {1} less to cast for each creature you control.
Double strike (This creature deals both first-strike and regular combat damage.)

Mutagen Man, Living Ooze

Trample
Activated abilities of artifact tokens you control cost {1} less to activate.
When Mutagen Man enters, create X Mutagen tokens. (They're artifacts with "{1}, {T}, Sacrifice this token: Put a +1/+1 counter on target creature. Activate only as a sorcery.")

The Last Ronin

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Destroy all creatures.
II — Mill four cards. When you do, return target creature card from your graveyard to your hand.
III — Whenever a creature you control attacks alone this turn, put three +1/+1 counters on it. It gains trample, lifelink, and indestructible until end of turn.

All Will Be One

Whenever you put one or more counters on a permanent or player, this enchantment deals that much damage to target opponent, creature an opponent controls, or planeswalker an opponent controls.

Leonardo's Technique

Sneak {1}{W} (You may cast this spell for {1}{W} if you also return an unblocked attacker you control to hand during the declare blockers step.)
Return one or two target creature cards each with mana value 3 or less from your graveyard to the battlefield.

Krang & Shredder

Whenever Krang & Shredder enter or attack, each opponent exiles cards from the top of their library until they exile a nonland card.
Disappear — At the beginning of your end step, if a permanent left the battlefield under your control this turn, you may cast a card exiled with Krang & Shredder without paying its mana cost.

Cytoplast Manipulator

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.)
{U}, {T}: Gain control of target creature with a +1/+1 counter on it for as long as this creature remains on the battlefield.

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.")

Anger

Haste
As long as this card is in your graveyard and you control a Mountain, creatures you control have haste.

Manhole Missile

Manhole Missile deals 3 damage to target creature. You may put a card from your hand on the bottom of your library. If you do, draw a card.

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Donatello's Technique

Sneak {U} (You may cast this spell for {U} if you also return an unblocked attacker you control to hand during the declare blockers step.)
Draw two cards.

The Ooze

Whenever a creature you control with a +1/+1 counter on it leaves the battlefield, create a Mutagen token for each +1/+1 counter on it. (A Mutagen token is an artifact with "{1}, {T}, Sacrifice this token: Put a +1/+1 counter on target creature. Activate only as a sorcery.")
{T}: Exile target card from a graveyard. Create a Mutagen token.

Pain 101

Until end of turn, target creature gains deathtouch and "When this creature dies, return it to the battlefield tapped under its owner's control."

North Wind Avatar

Flying
When this creature enters, if you cast it, you may put a card you own from outside the game into your hand.

Retro-Mutation

Flash
Enchant creature
Enchanted creature is a Turtle with base power and toughness 0/1. It can't attack and loses all abilities. (It also loses all other creature types.)

Shadowspear

Equipped creature gets +1/+1 and has trample and lifelink.
{1}: Permanents your opponents control lose hexproof and indestructible until end of turn.
Equip {2}

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.

Super Shredder

Menace
Whenever another permanent leaves the battlefield, put a +1/+1 counter on Super Shredder.

Make Your Move

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

Raphael, Tag Team Tough

Menace (This creature can't be blocked except by two or more creatures.)
Whenever Raphael deals combat damage to a player for the first time each turn, untap all attacking creatures. After this combat phase, there is an additional combat phase.

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Donatello, Way with Machines

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

Ooze Spill

Counter target spell. 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.")

Michelangelo, Improviser

Sneak {2}{G}{G} (You may cast this spell for {2}{G}{G} if you also return an unblocked attacker you control to hand during the declare blockers step. He enters tapped and attacking.)
Whenever Michelangelo deals combat damage to a player, you may put a creature card and/or a land card from your hand onto the battlefield.

Uneasy Alliance

Enchant creature
Enchanted creature can't attack or block.
{5}, Sacrifice this Aura: Exile enchanted creature. You create a 1/1 black Ninja creature token. Activate only as a sorcery.

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.")

Turncoat Kunoichi

Sneak {2}{W}{B} (You may cast this spell for {2}{W}{B} if you also return an unblocked attacker you control to hand during the declare blockers step. It enters tapped and attacking.)
When this creature enters, choose target creature an opponent controls. Exile that creature until this creature leaves the battlefield. If this creature's sneak cost was paid, instead exile the chosen creature.

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.)

Punk Frogs

Ward {3} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {3}.)

Tenderize

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

Death in the Family

Exile target creature with mana value 3 or less.

Hardened Scales

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.

Mutant Chain Reaction

Destroy up to one target artifact, enchantment, or creature with flying. 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.")

Michelangelo, On the Scene

Trample (This creature can deal excess combat damage to the player it's attacking.)
Michelangelo enters with a +1/+1 counter on him for each land you control.
When Michelangelo dies, return this card to your hand.

Conqueror's Flail

Equipped creature gets +1/+1 for each color among permanents you control.
As long as this Equipment is attached to a creature, your opponents can't cast spells during your turn.
Equip {2}

Teleportation Circle

At the beginning of your end step, exile up to one target artifact or creature you control, then return that card to the battlefield under its owner's control.

Turtles Forever

Search your library and/or outside the game for exactly four legendary creature cards you own with different names, then reveal those cards. An opponent chooses two of them. Put the chosen cards into your hand and shuffle the rest into your library.

Slash, Reptile Rampager

Alliance — Whenever another creature you control enters, Slash deals 2 damage to each opponent.
Whenever Slash attacks, create a 2/2 red Mutant creature token.

Containment Protocol

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

Kitsune's Technique

Sneak {1}{U} (You may cast this spell for {1}{U} if you also return an unblocked attacker you control to hand during the declare blockers step.)
Target opponent mills half their library, rounded up.

Squirrelanoids

Tainted Treats

Destroy target artifact or creature. If its mana value was 4 or less, 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.

Dimensional Exile

Enchant basic land you control
When this Aura enters, exile target creature an opponent controls until this Aura leaves the battlefield.

Splinter's Technique

Sneak {1}{B} (You may cast this spell for {1}{B} if you also return an unblocked attacker you control to hand during the declare blockers step.)
Search your library for a card, put that card into your hand, then shuffle.

Umezawa's Jitte

Whenever equipped creature deals combat damage, put two charge counters on Umezawa's Jitte.
Remove a charge counter from Umezawa's Jitte: Choose one —
• Equipped creature gets +2/+2 until end of turn.
• Target creature gets -1/-1 until end of turn.
• You gain 2 life.
Equip {2}

Turtles in Time

Return all creatures to their owners' hands. Each player may shuffle their hand and graveyard into their library, then each player who does draws seven cards.
Exile Turtles in Time.

Leonardo, Leader in Blue

Sneak {3}{W}{W} (You may cast this spell for {3}{W}{W} if you also return an unblocked attacker you control to hand during the declare blockers step. He enters tapped and attacking.)
When Leonardo enters, if his sneak cost was paid, creatures you control get +2/+0 until end of turn.
{1}{W}: Leonardo gains first strike until end of turn.

Raph's Bravado

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

Karai, Future of the Foot

Sneak {2}{W}{B} (You may cast this spell for {2}{W}{B} if you also return an unblocked attacker you control to hand during the declare blockers step. She enters tapped and attacking.)
Whenever Karai deals combat damage to a player, return target creature card from your graveyard to your hand. If her sneak cost was paid this turn, instead return that card to the battlefield.

Study the Classics

Put a +1/+1 counter on target creature, then double the number of +1/+1 counters on it. You gain life equal to the number of +1/+1 counters on that creature.

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.

Leader's Talent

(Gain the next level as a sorcery to add its ability.)
Whenever you attack, put a +1/+1 counter on target attacking creature.
{2}{W}: Level 2
Whenever a creature you control leaves the battlefield, if it had a counter on it, you gain 2 life.
{3}{W}: Level 3
Whenever you cast a spell, put a +1/+1 counter on each creature you control.

April O'Neil, Kunoichi Trainee

When April O'Neil enters, 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.)
April O'Neil can't be blocked by creatures with power 3 or greater.

Negate

Bebop, Warthog Warrior

Menace (This creature can't be blocked except by two or more creatures.)
Rhinos you control have menace.
Swampcycling {2} ({2}, Discard this card: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.)

Leonardo, Sewer Samurai

Sneak {2}{W}{W}
Double strike
During your turn, you may cast creature spells with power or toughness 1 or less from your graveyard. If you cast a spell this way, that creature enters with a finality counter on it. (If a creature with a finality counter on it would die, exile it instead.)

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.)

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.

Ink-Eyes, Servant of Oni

Ninjutsu {3}{B}{B} ({3}{B}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Ink-Eyes deals combat damage to a player, you may put target creature card from that player's graveyard onto the battlefield under your control.
{1}{B}: Regenerate Ink-Eyes.

Raphael, the Nightwatcher

Sneak {1}{R}{R} (You may cast this spell for {1}{R}{R} if you also return an unblocked attacker you control to hand during the declare blockers step. He enters tapped and attacking.)
Attacking creatures you control have double strike.

Michelangelo, Weirdness to 11

When Michelangelo 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.")
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.

Pizza Face, Gastromancer

When Pizza Face enters, create a Food token.
Disappear — At the beginning of your end step, if a permanent left the battlefield under your control this turn, put three +1/+1 counters on up to one other target artifact or creature. If it isn't a creature, it becomes a 0/0 Mutant creature in addition to its other types.
{10}, {T}, Sacrifice Pizza Face: You gain 15 life.

Rocksteady, Crash Courser

Rocksteady can't be blocked by more than one creature.
Boars you control can't be blocked by more than one creature.
Forestcycling {2} ({2}, Discard this card: Search your library for a Forest card, reveal it, put it into your hand, then shuffle.)

Transdimensional Bovine

Flying
{T}: Add two mana of any one color.

Ninja Teen

(Gain the next level as a sorcery to add its ability.)
Whenever a creature you control leaves the battlefield, each opponent loses 1 life.
{1}{B}: Level 2
Creatures you control get +1/+0 and have menace.
{B}: Level 3
Creature cards in your graveyard have sneak {3}{B}.
You may cast creature spells from your graveyard using their sneak abilities.

Chord of Calling

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.)
Search your library for a creature card with mana value X or less, put it onto the battlefield, then shuffle.

Michelangelo, Mutant BFF

Each creature you control with a counter on it can't be blocked by more than one creature.
Whenever Michelangelo enters or attacks, 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.")

Cowabunga!

Look at the top four cards of your library. You may reveal a Mutant, Ninja, Turtle, or land card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Prehistoric Turtlesaurus

This spell costs {1} less to cast if you control a creature with a +1/+1 counter on it.
Vigilance (Attacking doesn't cause this creature to tap.)

Raphael, Tough Turtle

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

Jennika, Bad Apple Big Sister

When Jennika enters, create a 2/2 red Mutant creature token.
Plainscycling {2} ({2}, Discard this card: Search your library for a Plains card, reveal it, put it into your hand, then shuffle.)

Sword of Sinew and Steel

Equipped creature gets +2/+2 and has protection from black and from red.
Whenever equipped creature deals combat damage to a player, destroy up to one target planeswalker and up to one target artifact.
Equip {2}

Leonardo, Big Brother

Sneak {W} (You may cast this spell for {W} if you also return an unblocked attacker you control to hand during the declare blockers step. He enters tapped and attacking.)
Leonardo gets +1/+0 for each other creature you control.

Trouble in Pairs

If an opponent would begin an extra turn, that player skips that turn instead.
Whenever an opponent attacks you with two or more creatures, draws their second card each turn, or casts their second spell each turn, you draw a card.

Turtle Power!

Foe-liage

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

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.

Genghis Frog

Trample
Whenever Genghis Frog or another Mutant you control 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.")

Dark Leo & Shredder

Sneak {W}{B}
Attacking Ninjas you control have deathtouch.
Whenever Dark Leo & Shredder deal combat damage to a player, create a 1/1 black Ninja creature token. Then if you control five or more Ninjas, that player loses half their life, rounded up.

New Generation's Technique

Sneak {2}{G} (You may cast this spell for {2}{G} if you also return an unblocked attacker you control to hand during the declare blockers step.)
Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Settle the Wreckage

Exile all attacking creatures target player controls. That player may search their library for that many basic land cards, put those cards onto the battlefield tapped, then shuffle.

Mondo Gecko

{1}, Discard a card: Until end of turn, Mondo Gecko becomes the color of your choice and gains hexproof from that color.
Whenever Mondo Gecko deals combat damage to a player, draw a card for each color among permanents you control.

High-Flying Ace

Flying
{3}{W}: Target creature without flying gains flying until end of turn. Activate only as a sorcery.

Metallic Mimic

As this creature enters, choose a creature type.
This creature is the chosen type in addition to its other types.
Each other creature you control of the chosen type enters with an additional +1/+1 counter on it.

Waves of Aggression

Untap all creatures that attacked this turn. After this main phase, there is an additional combat phase followed by an additional main phase.
Retrace (You may cast this card from your graveyard by discarding a land card in addition to paying its other costs.)

Leonardo, Cutting Edge

Sneak {W} (You may cast this spell for {W} if you also return an unblocked attacker you control to hand during the declare blockers step. He enters tapped and attacking.)
Lifelink
Whenever you gain life, put a +1/+1 counter on Leonardo.

Sally Pride, Lioness Leader

When Sally Pride enters, create X 2/2 red Mutant creature tokens, where X is the number of nontoken creatures you control.
Whenever Sally Pride attacks, put a +1/+1 counter on each creature you control.

Manhole Cover

Flash (You may cast this spell any time you could cast an instant.)
When this artifact enters, target creature gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)
{2}, Sacrifice this artifact: Target player draws a card.

Splinter, Radical Rat

If an ability of a Ninja creature you control triggers, that ability triggers an additional time.
{1}{U}: Target Ninja can't be blocked this turn.

Skateboard

When this Equipment enters, tap target permanent.
Equipped creature gets +1/+0 and has haste.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Shredder, Unrelenting

Sneak {3}{B} (You may cast this spell for {3}{B} if you also return an unblocked attacker you control to hand during the declare blockers step. He enters tapped and attacking.)
Deathtouch
Whenever Shredder enters or attacks, another target creature you control gains deathtouch until end of turn.

Metalhead

When Metalhead enters, return up to one other target artifact or creature to its owner's hand.
{R}, Sacrifice another artifact: Put a +1/+1 counter on Metalhead. He gains menace and haste until end of turn.

Doubling Season

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.
If an effect would put one or more counters on a permanent you control, it puts twice that many of those counters on that permanent instead.

Mikey & Leo, Chaos & Order

Whenever you put a counter on a creature you control, draw a card. This ability triggers only once each turn.

Agent Bishop, Man in Black

At the beginning of combat on your turn, put a +1/+1 counter on each of up to two target creatures.

Frog Butler

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