Give a fin-tastic, fairy-tale makeover to your toddler this Halloween with the Mystical Waters Mermaid Halloween Costume Dress from Hyde & EEK! Boutique. Made from soft fabric for comfortable wear during Halloween parties or trick-or-treating, this costume dress has a pink-and-purple bodice and a mermaid skirt with vibrant scales. Finished with shimmery light blue mesh fabric accents, this dress is sure to have your child feeling like a real mermaid. Hyde & EEK! Boutique: Thrilling delights. Curious oddities.