American Grotesque is a lavish retrospective of grotesque, occult, and erotic images by the forgotten Hollywood photographer William Mortensen (1897–1965), an innovative pictorialist visionary whom Ansel Adams called the "Antichrist" and to whom Anton LaVey dedicated The Satanic Bible.

Mortensen's countless technical innovations and inspired use of special effects prefigures the development of digital manipulation and Photoshop. Includes a gallery of more than one hundred striking photographs in duotone and color, many of them previously unseen, and accompanying essays by Mortensen and others on his life, work, techniques, and influence.