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.

Mouser Mark III

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

Rock Soldiers

When this creature enters, destroy up to one target noncreature artifact.

Mutant Town Musicians

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

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.")

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.

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.

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.

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.

Purple Dragon Punks

{T}: Add {R}. Spend this mana only to cast an artifact spell or to activate an ability.

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.)

Donatello, Way with Machines

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

Mountain

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.

Raphael, Tough Turtle

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

Escape Tunnel

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
{T}, Sacrifice this land: Target creature with power 2 or less can't be blocked this turn.

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.

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.

Turtle Van

Whenever this Vehicle attacks, put a +1/+1 counter on target creature that crewed it this turn. Then if that creature is a Mutant, Ninja, or Turtle, double the number of +1/+1 counters on it.
Crew 1 (Tap any number of creatures you control with total power 1 or more: This Vehicle becomes an artifact creature until end of turn.)