C.S. Lewis named the fictional demon who writes the letters in his 1942 book Screwtape.
The Screwtape Letters is structured as correspondence from Screwtape, a senior demon, to his junior assistant Wormwood. The letters offer advice about tempting a human patient, but Lewis uses the reversed viewpoint to criticize vanity, distraction, resentment, and self-deception.
The book was first published in 1942 and became one of Lewis’s most widely read works. Its imaginative method lets readers see familiar moral failures from an intentionally hostile perspective. Screwtape’s apparent expertise also creates irony, because the demons’ language exposes their own limitations and distortions.
Wormwood is the junior demon receiving the letters, so he is a common mistaken answer when a question asks for the writer. The title itself supplies the key: the letters are “Screwtape’s,” and Screwtape is the senior correspondent. Lewis later added a preface discussing the difficulties of writing from a demonic point of view.