Personalized 4th Birthday Cute Penguin Women's V-Neck T-Shirt. 4th Birthday Women's V-Neck T-Shirt - Pink has cute penguin in a party hat with the number 4 on its tummy for your child's fourth birthday celebration. 5.0 oz., 100% pre-shrunk cotton Athletic Heather is 90/10 cotton/polyester 1x1 rib collar with mitered v-neck Shoulder-to-shoulder taping Ladies' fit