Personalized This will be the Best Birthday Ever Youth Long Sleeve T-Shirt. While all birthdays are worth celebrating, this one will be the best ever! This will be the Best Birthday Ever Youth Long Sleeve T-Shirt - White, featuring Mouse from the children's book "Dog and Mouse" my Michelle Nelson-Schmidt. youth long sleeve t-shirt. Shoulder-to-shoulder taping. Youth: S(6/8), M(10/12), L(14/16), XL(18/20)