Personalized 3rd Birthday Bear 3 Year Old Outfit Youth Long Sleeve T-Shirt. Cute bear with I'm three quote for a little boy or girl turning three years old comes on this 3rd birthday Youth Long Sleeve T-Shirt - White. youth long sleeve t-shirt. Shoulder-to-shoulder taping. Youth: S(6/8), M(10/12), L(14/16), XL(18/20)