|Cover artist||Roy Kuhlman|
|Media type||Print (Hardback & Paperback)|
|Pages||Approx. 245 pages|
|Dewey Decimal||813/.54 19|
|LC Class||PS3521.E735 D63 1987|
|Preceded by||The Dharma Bums
|Followed by||Maggie Cassidy
The novel begins with Jackie Duluoz, based on Kerouac himself, relating a dream in which he finds himself in Lowell, Massachusetts, his childhood home town. Prompted by this dream, he recollects the story of his childhood of warm browns and sepia tones, along with his shrouded childhood fantasies, which have become inextricable from the memories.
The fantasies pertain to a castle in Lowell atop a muted green hill that Jackie calls Snake Hill. Underneath the misty grey castle, the Great World Snake sleeps. Various vampires, monsters, gnomes, werewolves, and dark magicians from all over the world gather to the mansion with the intention of awakening the Snake so that it will devour the entire world (although a small minority of them, derisively called "Dovists," believe that the Snake is merely "a husk of doves," and when it awakens it will burst open, releasing thousands of lace white doves. This myth is also present in a story told by Kerouac's character, Sal Paradise, in On the Road).
The eponymous Doctor Sax, also part of Jackie's fantasy world, is a dark but ultimately friendly figure with a shrouded black cape, an inky black slouch hat, a haunting laugh, and a "disease of the night" called Visagus Nightsoil that causes his skin to turn mossy green at night. Sax, who also came to Lowell because of the Great World Snake, lives in the forest in the neighboring town of Dracut, where he conducts various alchemical experiments, attempting to concoct a potion to destroy the Snake when it awakens.
When the Snake is finally awakened, Doctor Sax uses his potion on the Snake, but the potion fails to do any damage. Sax, defeated, discards his shadowy black costume and watches the events unfold as an ordinary man. As the Snake prepares to destroy the world, all seems lost until an enormous night colored bird, an ancient counterpart of the Snake, suddenly appears. Seizing the Snake in its beak, the bird flies upward into the heartbreakingly blue sky until it vanishes from view, leading the amazed Sax to muse, "I'll be damned, the universe disposes of its own evil!"
Kerouac often based his fictional characters on friends and family.
"Because of the objections of my early publishers I was not allowed to use the same personae names in each work." 
|Real-life person||Character name|
|Leo Kerouac||Emil "Pop" Duluoz|
|Gerard Kerouac||Gerard Duluoz|
|Caroline Kerouac||Catherine "Nin" Duluoz|
|George "G.J." Apostolos||Rigopoulos|
|Henry "Scotty" Beaulieu||Paul "Scotty" Boldieu|
|Fred Bertrand||Vinny Bergerac|
|"Happy" Bertrand||Lucky Bergerac|
|Leona "Leo" Bertrand||Charlie Bergerac|
|Billy Chandler||Dickie Hampshire|
|Duke Chungas||Bruno Gringas|
|Omar Noel||Ali Zaza|
|Roland Salvas||Albert "Lousy" Lauzon|
Doctor Sax and the Great World Snake
Kerouac also wrote a screenplay adaptation of the novel entitled Doctor Sax and the Great World Snake. It was never filmed, but in 1998, Kerouac's nephew Jim Sampas discovered the text in Kerouac's archives. He proceeded to produce the piece in audio form, much like a radio drama, and release it in 2003 from his independent record label, Gallery Six (named for the site of the famous Six Gallery reading), in a partnership with Mitch Winston's record label, Kid Lightning Enterprises. The release consisted of two CDs and a book containing the screenplay with illustrations by Richard Sala.
In other media
Doctor Sax appeared in The League of Extraordinary Gentlemen: Black Dossier by Alan Moore in a story written by Sal Paradise (from Kerouac's On the Road). He is mentioned as being the great-grandson of The Devil Doctor (because of the Doctor's creator, Sax Rohmer) and fights against Mina Murray, Allan Quatermain, Paradise and Dean Moriarty (who is the great-grandson of Manchu's rival and Sherlock Holmes' nemesis Professor Moriarty).
- Who’s Who: A Guide to Kerouac’s Characters
- Kerouac, Jack. Visions of Cody. London and New York: Penguin Books Ltd. 1993.