Katarzyna Onyszkiewiczowa (1840 – March 9, 1895), known as The Female Demon (Polish: Demon Kobiecy) among other purported names, was a Polish thief and serial killer who was responsible for at least three murders in Galicia from 1869 to 1870. She was convicted of these deaths in separate trials, and eventually died behind bars while serving one of her sentences.
