Oct. 31 is a night for villains, which is great news for women’s Halloween costume ideas, and even better news for Shego from Disney’s Kim Possible. She is evil—has she made herself clear?

Not to mention, Heidi Klum’s memorable snail costume debuted at one of her many star-studded Halloween parties. This autumn, we encourage shoppers to follow suit and think outside the box.

3. The Little Mermaid “A Disney princess is one of the most classic Halloween costumes for women, so last year I dressed up as the live action Ariel (played by Halle Bailey),” Candelario says ...