Personalized I'm 5 Dinosaur Youth Long Sleeve T-Shirt. I'm 5! A grinning dinosaur wearing a birthday hat rips through the background to wish your little one a happy birthday! Great gift for your five year old. youth long sleeve t-shirt. Shoulder-to-shoulder taping. Youth: S(6/8), M(10/12), L(14/16), XL(18/20)