Personalized Hoot Owl I'm Going to be a Big Brother T-Shirt. Whether your little one is preparing to welcome a baby brother or sister, this cute and funny design will surely bring smiles and laughter. It's a wonderful keepsake for parents and children alike as they embark on this new adventure together. 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.