The phrase references a themed attire choice for the Halloween holiday, specifically designed to resemble a cartoon character. The subject is identifiable by its characteristics: a rodent known for storing nuts, combined with a designation to a time of celebration involving dressing up in disguises. An example would be a child wearing a suit mimicking the appearance of an animated character associated with underwater adventures, modified for the purpose of trick-or-treating.
The popularity stems from the desire to embody familiar and beloved characters during festive occasions. This type of ensemble allows individuals, particularly children, to express their fandom and engage in imaginative play. Historically, costuming traditions have evolved from ritualistic practices to contemporary celebrations, where participants embrace opportunities for creative expression and social interaction through thematic apparel.