Personalized 1st Birthday Cute Dinosaur Long Sleeve T-Shirt. It's your child's first birthday, and this adorable dinosaur is celebrating! Adorable tee shirt for baby's 1st birthday. Pre-shrunk 100% cotton 6.1 ounce long sleeve t-shirt. Double-needle stitched neckline and sleeves. Quarter turned. Shoulder-to-shoulder taping. Adult: S, M, L, XL, 2XL, 3XL