Ariel is the main character in the 1989 Disney film The Little Mermaid. Ariel has long red hair, deep blue eyes and a green mermaid tail. Her only item of clothing is a bra made from purple seashells. For an Ariel costume you will need a sparkly bra or corset preferably with a seashell like design and a “mermaid cut” dress with a flared bottom that looks like a tail. A tutu style bottom also works great and is easier to walk around in than a tail that has a lot of material that touches the ground.