Personalized 4th Birthday Cute Penguin Long Sleeve T-Shirt. 4th Birthday Long Sleeve T-Shirt - Pink has cute penguin in a party hat with the number 4 on its tummy for your child's fourth birthday celebration. Pre-shrunk 100% cotton 6.1 ounce long sleeve t-shirt. Double-needle stitched neckline and sleeves. Quarter turned. Shoulder-to-shoulder taping. Adult: S, M, L, XL, 2XL, 3XL