Personalized First Birthday Happy Owl T-Shirt. Our 1st Birthday Look Who's One Owl Birthday design is ideal for celebrating your baby's first year of life. The cartoon owl adds a playful touch, making it a fun and festive choice for the occasion. Whether you're looking for invitations, decorations, or party favors, our design is versatile and can be used in a variety of ways to make the celebration extra special. 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.