Don & Raph, Hard Science

Menace
Whenever Don & Raph attack, the next noncreature spell you cast this turn has affinity for artifacts. (It costs {1} less to cast for each artifact you control.)

Karai's Technique

Sneak {W}{B} (You may cast this spell for {W}{B} if you also return an unblocked attacker you control to hand during the declare blockers step.)
Choose one or both —
• Target creature gets +3/+3 until end of turn.
• Target creature gets -3/-3 until end of turn.

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.

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.

Mikey & Leo, Chaos & Order

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

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.

Raph & Leo, Sibling Rivals

Whenever Raph & Leo attack, if it's the first combat phase of the turn, untap one or two target attacking creatures. After this phase, there is an additional combat phase.

Triceraton Commander

Dinosaur Soldier

Flying
Whenever this creature attacks, Dinosaurs you control other than this creature get +1/+1 and gain flying until end of turn.
When this creature enters, create X 2/2 white Dinosaur Soldier creature tokens.

Raph & Mikey, Troublemakers

Trample, haste
Whenever Raph & Mikey attack, reveal cards from the top of your library until you reveal a creature card. Put that card onto the battlefield tapped and attacking and the rest on the bottom of your library in a random order.

Splinter, Radical Rat

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

Tokka & Rahzar, Terrible Twos

This spell can't be countered.
Menace
Whenever a player casts a spell, if the amount of mana spent to cast it was less than its mana value, Tokka & Rahzar deal 3 damage to that player.

Teenage Mutant Ninja Turtles