Hell icons (Russian: Адописная икона, Adopisnaya ikona, lit. "Hell-written icon" or "of a Hell descent icon") are legendary icons with images of Devil hidden under primer, robe or painted layer. Also, the image of saint could include horns, hidden under the paint.
The term "Hell-created" first occurs in Prologue (Eastern Orthodox Synaxarium) regarding Sabellianist church banners. Full Church Slavonic dictionary gives the following commentary: "painted in hell". The term "Hell icons" is known mostly amongst Old Believers. Hell icons painting, known as Adopis, "hellography" (as opposed to iconography), was also a type of black magic in medieval Russia.
Hell icons were first mentioned in the Life of St. Basil (16th century). Basil threw a rock at the icon of Virgin Mary before the eyes of the astonished crowd of pilgrims. Then he allegedly showed that an image of the devil was hidden under the paint.
Messages about hell icons appeared in newspaper articles and literature of the 19th century. But such articles reported only the later icons of "cheap and clumsily painting." Interested in Christian iconography, Nikolai Leskov included a reference to hell icons in his story The Sealed Angel (1872) and in short article "About the hell icons" (Russian: Об адописных иконах), published in 1873.
Despite these studies of hell icons, in the 20th century Russian linguist Nikita Tolstoy doubted the fact of their real existence. This point of view is shared by modern art critics due to lack of material evidence (all such icons, if ever existed, have been lost).