Personalized T-Rex Dinosaur 4th Birthday Toddler T-Shirt. A grumpy, purple T-Rex wearing a birthday hat sits and eats a birthday cupcake. Cute 4th birthday gift for your little four year old. 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.