Personalized 3rd Birthday Monster Truck Toddler T-Shirt. 3rd Birthday Monster Truck Toddler T-Shirt - Heather and Royal for boys turning three years old. Colorful confetti and number 3 add a party feel to this bday design. 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.