This article examines the way, in which the idea of making a new man by changing human nature, globally accentuated in the 1920—1930s, was reflected in two works produced at the time: in James Whale’s cinematic blockbuster Frankenstein and Mikhail Bulgakov’s novella Heart of a Dog. The two works are placed together because, besides employing the common theme of out-of-control monsters, they provide a similar “dysgenic” explanation of their behavior: the brains of these characters are abnormal. The comparison of the two plots highlights the specific fears and dominating challenges of the decades marked by eugenic battles at the crossroads of biology, medicine, pedagogics, sociology, and forensic psychiatry.