Personalized 5th Birthday Mermaid Long Sleeve T-Shirt. Cute mermaid princess rides on her rainbow seahorse and surrounded by her fish friends. Happy birthday to the 5 year old on her 5th birthday. Pre-shrunk 100% cotton 6.1 ounce long sleeve t-shirt. Double-needle stitched neckline and sleeves. Quarter turned. Shoulder-to-shoulder taping. Adult: S, M, L, XL, 2XL, 3XL