It's still Friday somewhere, and today's obscure opus is The Manuscript Found in Saragossa by Jan Potocki
Originally published in 1847, 30 years after the author's death by suicide, and supposedly unfinished, but no one really knows, this mad travelogue recounts the 66 days of the narrator's journey through Andalusia during the 1700s, and manages to explore the tropes of horror with an almost slapstick abandon, throwing everything including incest, necrophilia, hauntings, the walking dead, sex changes, shapeshifting....and that's in just 4 pages of one story within this monumental work of inspired lunacy.
Trivia Tidbits: Although Potocki was Polish, this novel was originally written in French.
Adapted in 1965 by director Wojciech Has into the Polish black and white film The Sargossa Manuscript. The film was admired by such individuals as Grateful Dead guitarist Jerry Garcia, Martin Scorsese, and Francis Ford Coppola.