Personalized My Mommy is the Worlds Best Aeronautical Engineer Toddler T-Shirt. This My Mommy is the Worlds Best Aeronautical engineer Toddler T-Shirt - White has worlds best design for kids with my mommy is the worlds best aeronautical engineer occupation slogan for the son or daughter of a Aeronautical engineer. A toddler-soft cotton tee in look-at-me, big kid colors. 4.5 oz., 100% combed ringspun cotton. White is sewn with 100% cotton thread. Topstitched rib crew neck. Double-needle stitched sleeves and bottom hem. Shoulder-to-shoulder taping.