The Optimus Prime Muscle Child Halloween Costume makes a colorful and exciting outfit for the holiday. It is ideal to use for trick-or-treating or to use for dress-up clothes just for fun. Its lightweight cut allows for free and easy movement. This Transformers costume for kids also features torso and arm muscle padding, creating a look of strength to battle the enemy. It has shoulder fins that sit at an angle, and it comes with a realistic-looking full mask.