Personalized 3rd Birthday Bear 3 Year Old Outfit Youth 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 T-Shirt - White. Let the good times roll in a durable T-Shirt that takes kids from school to play in an amazing array of colors. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar.