Got ninja skills but no ninja costume? The solution is simple... a plain, black T-shirt. That's pretty much all it takes to be one hell of a badass ninja on Halloween. Well, you should also wear a completely black matching outfit that has long sleeves and pant legs.
Take a black tee shirt and turn it inside out. Wear it over your head so that your eyes peek through, then pull the sleeves together in the back. Make sure your eyes are visible and tie the sleeves together in the back. After this, you should have only an open space showing your eyes.
Now just wear gloves on your hands and get ready to go out on a stealthy trick-or-treat mission.