This article focuses on associations between early modern English witchcraft, demonic activity, temptation and transformation, and the night. It has a particular emphasis on “nightmare” encounters, a term used here not in the modern sense of a bad dream but in the premodern sense of a physical assault by a supernatural being. In most early modern nightmare encounters, victims reported that it was either the Devil or, more commonly, a witch assaulting them in the night. However, in stories of accused witches reporting nightmare encounters, we see a distinctly different belief: that devils could lie on potential witches as part of a process of demonic temptation and transformation. In this article I will argue that these nightmare encounters represented a physical manifestation of an internal struggle against Satan. In doing so I will revisit and reinterpret current scholarship on the nightmare and reinforce the importance of the demonic in English witchcraft belief.