Personalized I'm One Dinosaur Toddler T-Shirt. I'm One! A grinning dinosaur wearing a birthday hat rips through the shirt to wish the little one year old a happy 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.