Cassandra Peterson was born in Manhattan, Kansas. At age seventeen, she became the youngest showgirl in Las Vegas history, and after receiving advice from the King himself, Elvis Presley, she traveled to Europe where she pursued a career as a singer and actor. Upon returning to the States, Peterson toured America as star of her own musical-comedy show, Mama's Boys . She eventually settled in Hollywood, where she spent four years with The Groundlings, Los Angeles's foremost improvisational comedy group. In 1981, she created the character Elvira, Mistress of the Dark, for a local Los Angeles television station. Elvira and her show, Movie Macabre , became an overnight sensation and was soon picked up by stations across the country. Peterson cowrote, produced, and starred in two feature-length films: Elvira: Mistress of the Dark and Elvira's Haunted Hills . In 2021, she published her memoir, Yours Cruelly, Elvira , which became a New York Times bestseller.

Peterson has spent over four decades solidifying the Elvira brand, one that has become synonymous with Halloween and the horror genre.