Personalized Rawr I'm One Dinosaur Women's V-Neck T-Shirt. Rawr! I'm One! A cute T Rex dinosaur holding a megaphone and wearing a birthday party hat roars to let everyone know its birthday is here. Cute gift for your one year old's 1st birthday. 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