Lobismuller.

Lobismuller tells the story of Manuel Blanco Romasanta, Spain's bloodiest and most enigmatic serial killer, from a female perspective. Manuel was born Manuela and originally believed to be a woman: according to modern forensic theories, he (or she) may have lived with a rare syndrome of intersexuality. Blanco Romasanta was dubbed the "Soapmaker," owing to his habit of using the fat of victims to produce high-quality soap. Although confessing to nine of the seventeen murders now attributed to him, Blanco Romasanta pleaded not guilty, declaring himself the victim of a curse that had transformed him into a wolf. (Source: https://www.anzenbergergallery/bookshop.com).