Personalized 1st Day of School Mermaid Tail Youth T-Shirt. 1st day of school Youth T-Shirt - Vintage Royal Blue with cute mermaid tail for girls 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.