Ergotism, the disease caused by consuming Claviceps purpurea, a highly poisonous, grain-infecting fungus, occurred at various places scattered throughout Norway during the eighteenth and nineteenth centuries. By focusing on these cases we chart the changing interpretations of the peculiar disease, frequently understood within a religious context or considered as a supernatural (e.g. ghostly) experience. However, there was a growing awareness of the disease ergotism, and from the late eighteenth century onwards it was often correctly interpreted as being due to a fungus consumed via bread or porridge. Also, nineteenth-century fairy-tales and regional legends reveal that people were increasingly aware and fearful of the effects of consuming infected grain.