Turncoat Kunoichi (TMT-026) - Teenage Mutant Ninja Turtles

Sneak 2WB (You may cast this spell for 2WB if you also return an unblocked attacker you control to hand during the declare blockers step. It enters tapped and attacking.)

When this creature enters, choose target creature an opponent controls. Exile that creature until this creature leaves the battlefield. If this creature's sneak cost was paid, instead exile the chosen creature.