Personalized 1st Birthday Owl T-Shirt. Whether you're planning a small family gathering or a big birthday party, this 1st Birthday Look Who's One Owl Birthday design is sure to delight your guests. The design is ideal for a baby girl's first birthday, with its cheerful colors and charming owl character. Make your little one's milestone birthday even more special with this sweet and festive theme. 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.