Personalized Unicorn 3rd Birthday Toddler T-Shirt. Unicorn 3rd Birthday - A pastel unicorn jumps over a colorful rainbow and smiling cloud. Cute gift for the three year old's third 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.