Personalized I'm One Superhero Toddler T-Shirt. I'm One! Superhero toddler in a red cape and diaper is ready to fight crime and nap time. Cute gift for any superhero one year old's 1st birthday. A toddler-soft cotton tee in look-at-me, big kid colors. 4.5 oz., 100% combed ringspun cotton. White is sewn with 100% cotton thread. Topstitched rib crew neck. Double-needle stitched sleeves and bottom hem. Shoulder-to-shoulder taping.