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.

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.)

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.")

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.

Donatello, Mutant Mechanic

{T}: 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. Activate only as a sorcery.
Whenever an artifact you control is put into a graveyard from the battlefield, if it had counters on it, put those counters on up to one target artifact or creature you control.

Chrome Dome

Other artifact creatures you control get +1/+0.
{5}: Create a token that's a copy of another target artifact you control. That token gains haste. Sacrifice it at the beginning of the next end step.

Return to the Sewers

Target creature's owner puts it on their choice of the top or bottom of their library. 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.")

Donnie & April, Adorkable Duo

When Donnie & April enter, choose one or both. Each mode must target a different player.
• Target player draws two cards.
• Target player returns an artifact, instant, or sorcery card from their graveyard to their hand.

Roadkill Rodney

Squad {3} (As an additional cost to cast this spell, you may pay {3} any number of times. When this creature enters, create that many tokens that are copies of it.)
Deathtouch
Whenever this creature deals combat damage to a player, create a Mutagen token.

Donatello's Science Lesson

Tap up to two target creatures. Up to two target players each draw a card.

April O'Neil, Live on the Scene

Whenever a Mutant, Ninja, or Turtle you control enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")
Partner—Character select

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.

Donatello, the Brains

If one or more tokens would be created under your control, those tokens plus a Mutagen token are created instead.
Partner—Character select (You can have two commanders if both have this ability.)

Krang, Master Mind

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
When Krang enters, if you have fewer than four cards in hand, draw cards equal to the difference.
Krang gets +1/+0 for each other artifact you control.

Here Comes a New Hero!

Target player draws X cards. Create a token that's a copy of up to one target creature with mana value X or less.

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.")

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.

Technodrome

Reach, trample
This creature can't attack or block unless its power is 6 or greater.
{T}, Sacrifice another artifact: Draw a card. Put a +1/+1 counter on this creature.

Island

Fugitive Droid

This creature can't be blocked if an artifact entered the battlefield under your control this turn.
{U}, Sacrifice this creature: Counter target spell that targets an artifact or creature you control.

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.

Exploding Barrel

{T}: Add one mana of any color. Put a pressure counter on this artifact.
{8}, {T}, Sacrifice this artifact: It deals 20 damage to target creature. This ability costs {1} less to activate for each pressure counter on this artifact. Activate only as a sorcery.

Stockman, Mad Fly-entist

Flying
When Stockman enters, draw a card, then discard a card.
Islandcycling {2} ({2}, Discard this card: Search your library for an Island card, reveal it, put it into your hand, then shuffle.)

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.

Donatello, Gadget Master

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. He enters tapped and attacking.)
Whenever Donatello deals combat damage to a player, create a token that's a copy of target artifact you control.

Big Mother Mouser

This creature enters with two +1/+1 counters on it.
Whenever this creature attacks, double the number of +1/+1 counters on it.
When this creature dies, create a number of 1/1 colorless Robot artifact creature tokens equal to the number of +1/+1 counters on this creature.

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.

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.")

Buzz Bots

Flying, vigilance
When this creature dies, draw a card.

Donatello, Way with Machines

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

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.)