Personalized I'm Three Comic Book Long Sleeve T-Shirt. Pow! Cool! Ka-Boom! I'm Three! Cool comic book style birthday gift for any three year old superhero's 3rd birthday! Pre-shrunk 100% cotton 6.1 ounce long sleeve t-shirt. Double-needle stitched neckline and sleeves. Quarter turned. Shoulder-to-shoulder taping. Adult: S, M, L, XL, 2XL, 3XL