Tenderize

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

Negate

Does Machines

(Gain the next level as a sorcery to add its ability.)
When this Class enters, mill two cards, draw two cards, then discard two cards.
{1}{U}: Level 2
When this Class becomes level 2, return up to two target artifact cards from your graveyard to your hand.
{4}{U}: Level 3
At the beginning of combat on your turn, put three +1/+1 counters on target artifact you control. If it isn't a creature, it becomes a 0/0 Robot creature in addition to its other types.

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.

Slithering Cryptid

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.")

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.")

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.")

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.

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.

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.

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.

Mutant Town

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

Forest

Super Combo

Replicate {2} (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)
Target creature you control deals damage equal to its power to target creature an opponent controls.

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.")

Level Up

Enchant creature
When this Aura enters, put a +1/+1 counter on enchanted creature.
Enchanted creature has "Whenever this creature attacks, double the number of +1/+1 counters on it. Then if it has power 10 or greater, draw a card."

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.

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.

Mikey & Don, Party Planners

Ward {2}
You may look at the top card of your library any time.
You may play lands and cast Mutant, Ninja, or Turtle spells from the top of your library. If you cast a creature spell this way, that creature enters with an additional +1/+1 counter on it.

Turtle Power!

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.

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.")

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.

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.)

Leatherhead, Iron Gator

Trample, haste
Whenever Leatherhead attacks, put two +1/+1 counters on each creature you control.

Party Dude

(Gain the next level as a sorcery to add its ability.)
When this Class enters, each player creates a Food token.
{1}{G}: Level 2
Whenever an artifact an opponent controls is put into a graveyard from the battlefield, draw a card.
{4}{G}: Level 3
Whenever one or more of your opponents are attacked, up to one target attacking creature gets +X/+X until end of turn, where X is the number of cards in your hand.

Venus, Torn Between Worlds

Whenever Venus is dealt damage, put that many +1/+1 counters on her. (She must survive the damage to get the counters.)
Whenever a creature you control with a counter on it deals combat damage to a player, you may pay {U}. If you do, draw a card.

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}.)

Lessons from Life

Draw three cards. You may put a land card from your hand onto the battlefield tapped.

Bespoke Bō

When this Equipment enters, return up to one other target nonland permanent to its owner's hand.
Equipped creature gets +2/+1 and has vigilance.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

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.")

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.

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.

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.")

Vigor

Trample
If damage would be dealt to another creature you control, prevent that damage. Put a +1/+1 counter on that creature for each 1 damage prevented this way.
When Vigor is put into a graveyard from anywhere, shuffle it into its owner's library.

Baxter, Fly in the Ointment

Whenever Baxter enters or attacks, each creature you control with a counter on it gains flying until end of turn.
Whenever you draw a card, put a +1/+1 counter on Baxter.

Island

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.

Groundchuck & Dirtbag

Trample
Whenever you tap a land for mana, add {G}.

Rain-Slicked Copse

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