This chapter explores how Charles Darwin’s ideas about structural and functional anomalies in plants, animals and humans inspired the new Gothic monsters to be found in the work of Grant Allen, H. G. Wells, Robert Louis Stevenson, Bram Stoker and Arthur Machen. It traces the ways in which these writers reimagined human genealogies in light of evolutionary biology, materialism and Darwinist criminal anthropology. Sadistic criminals whose degenerate minds and bodies threatened civilised society, and atavistic flesh-eating plants whose natural ‘criminality’ was coaxed out by sadistic experimental scientists, are part of a significant reimagining of both biological and cultural history in the last half of the century. Indeed, through these types of biological monsters, Gothic writers challenged some of the most cherished ideas that Victorians held about their cultural heritage. Knowledge about human descent, the biology of human and animal abnormality, and criminal compulsions that dwelt in the ‘protoplasm’, largely negated the ideals of the age of chivalry – the medieval origins of the higher-order values that supposedly defined the human as exceptional.