There are a few Halloween costumes that fall under the "classics" category — think: witches, nurses, black cats, and mermaids. No matter what trendy memes or award-winning movies everyone is planning to recreate on October 31, these are the tried-and-true options that never feel outdated. Now, some might say dressing up as a mermaid for Halloween is boring, but we disagree; it's all about making it your own. And there's a reason mermaids are one of Pinterest's top costume searches , even in 2019.