Personalized Mermaid 2nd Birthday 2 Year Old Youth Long Sleeve T-Shirt. Cute 2nd birthday Youth Long Sleeve T-Shirt - Royal Blue that says this mermaid is two with a colorful mermaid tail and starfish youth long sleeve t-shirt. Shoulder-to-shoulder taping. Youth: S(6/8), M(10/12), L(14/16), XL(18/20)