Disney's The Little Mermaid Infant Sized Ariel Costume. Make Sure Your Little Mermaid is the Talk of the Tide Pool with This Gorgeous Costume! Quality Craftsmanship and Vibrant Colors Will Make Her the Cutest Princess Under The Sea. (She'll Definitely Out-Dazzle Flounder!) She'll be the life of the party, or a tail-shaking good time in the pool! With eye-catching details that are sure to make a splash, this costume is sure to be a fin-tastic night!