Freud's The Interpretation of Dreams denies itself any reference to the immemorial folklore and demonology of nightmares. This telling omission can be linked to the marginal role assigned to the affective dimension of dreams in Freud's book. It can also be linked to Freud's life-long struggle to determine the place of anxiety dreams in the framework of his dream theory. This conceptual problem became even more urgent when, in the wake of World War I, the anxiety dreams of traumatized soldiers appeared on the psychoanalytic agenda. Among Freud's closest collaborators, Ernest Jones was the first to turn his attention to the mythology of nightmares. Interestingly enough, Jones's study treats the nightmare complex exclusively as a problem of cultural theory instead of dream theory. In this essay I explore the theoretical implications of this half-forgotten chapter of psychoanalytic dream theory focusing on Freud, Jones and Ernst Simmel.