Personalized 1st Birthday Unicorn T-Shirt. A pink unicorn surrounded by a colorful rainbow, next to a sunny yellow 1. Cute gift for the birthday girl's first bday! Everyone loves our Custom T-Shirts! Wardrobe essential for looking good, 24/7. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar. Shoulder-to-shoulder taping. Double-needle stitched sleeves, bottom hem and front neck. Note: greys are a cotton/polyester blend.