Little Mermaid Hat for Girl - Ariel Hat Bundle with The Little Mermaid Baseball Cap for Kids Plus Stickers, More | Little Mermaid Baseball Hat for Girls, Kids. This Little Mermaid baseball cap set includes one Ariel hat with adjustable back strap and colorful artwork of Ariel and Flounder. This Little Mermaid cap for girls measures 6'' x 5'' x 10'' and with its adjustable back strap, it comfortably fits most young children's heads. Great for any fan of The Little Mermaid, this Ariel baseball hat is perfect to give as a gift to your favorite Disney Princess fan. Officially licensed The Little Mermaid hat for all kids, boys and girls alike, also comes with Disney Princess stickers and a Beach Kids princess castle door hanger.