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.

East Wind Avatar

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

Plains

Grounded for Life

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

Triceraton Regenta

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

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.")

Definitely Not a Turtle

When this creature dies, look at the top six cards of your library. You may reveal a land or legendary Turtle card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Action News Crew

Vigilance
Channel — {6}, Discard this card: Put a +1/+1 counter on each creature you control. Draw a card.

Splinter & Leo, Father & Son

When Splinter & Leo enter, choose one or both. Each mode must target a different player.
• Target player creates a 2/2 red Mutant creature token.
• Put a +1/+1 counter on each other creature target player controls.

Lita, Little Orphan Amphibian

Alliance — Whenever another creature you control enters, choose one that hasn't been chosen this turn.
• Put a +1/+1 counter on Lita.
• Create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")
• Scry 1.

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.

The Last Ronin'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.)
Create three 1/1 white Ninja Turtle Spirit creature tokens. If this spell's sneak cost was paid, they enter tapped and attacking.

Hamato Ninpō

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

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.)

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.)

Make Your Move

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

EPF Point Squad

Alliance — Whenever another creature you control enters, put a +1/+1 counter on this creature.

Leo's Guidance

Put a +1/+1 counter on each of up to three target creatures. Untap them.

Leonardo, Worldly Warrior

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

Splinter, Aging Champion

When Splinter enters, destroy up to one target tapped creature.
When Splinter leaves the battlefield, you and another target player each draw a card.

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.)

Wooden Cane

When this Equipment enters, create a 2/2 red Mutant creature token, then attach this Equipment to it.
Equipped creature gets +2/+1.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

High-Flying Ace

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

Mechanized Ninja Cavalry

When this creature enters, create a 1/1 colorless Robot artifact creature token.