Personalized Lucky Unicorn Toddler T-Shirt. Cute St. Patrick's Day Toddler T-Shirt - White with magical, green Irish unicorn and shamrocks says LUCKY. Luck O' The Irish unicorn lover novelty gift for parades and Irish St. Paddy's Day parties. 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.