Personalized Lucky Unicorn Toddler Long Sleeve T-Shirt. Cute St. Patrick's Day Toddler Long Sleeve Tee - 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 classic for Fall, Winter and Spring, these long sleeve toddler t-shirts are sure to be a staple in your child's wardrobe. Whether layered or alone, this t-shirt is soft yet durable enough to stand up to your toddler's playtime demands.