OED says:
doobie: a marijuana cigarette
Origin unknown. A relationship with dobby has been suggested.
dobby/dobbie: A silly old man, a dotard, a booby. Dialectal.First citations:
1967 J. B. Williams Narcotics & Hallucinogenics. Dubbe, Negro slang for a marijuana roach.
1982 A. Maupin Further Tales of City 95, I smoke a doobie at lunch.
But I just chanced upon What does the "dooby" in "scooby dooby doo" mean? in Yahoo Answers (don't laugh! 🙂 where someone posted:
"It's obvious that Shaggy's a stoner, I'm sure he's been feeding Scoob a bit of his hash and whatnot."
Scoob = Scooby Doo, cartoon "pet" dog of constantly-hungry hippie/village idiot Shaggy (from 1969)
I'm not entirely convinced that 1967 dubbe was necessarily a significant factor in the appearance of a doobie = a joint since around 1970 (the hippie era, some might say).
So I'd like to know whether it's credible to claim the usage arose (primarily?) through association with the TV show (specifically, the two characters therein closely associated with marijuana).
Best Answer
Shaggy from Scooby-Do was modeled on Maynard G. Krebs, a sidekick character in the early 60's sitcom The Many Loves of Dobie Gillis. In fact, all the main characters in Scooby-Do were modeled on Dobie Gillis characters.
Given that it was such a straight homage, if you were to try to argue a drug use subtext in the character design, you'd have to argue it from the original work. But there its generally assumed Krebs was just created originally as a generic beatnik. While drug use certainly was part of that culture, in the show most of the subtexts seemed to involve Krebs' issues with work, marriage, and the police (any mention of those three words caused him to yelp in fear, or worse).
The "Shaggy was obviously a stoner; that's why he always had the munchies!" meme is something I've mostly heard in the last decade or so, long after the show was off the air and started to be analyzed by a new generation of adults, much like the "Peppermint Patty is a lesbian" argument that I never heard until the 90's. IMHO that's just as likely people with modern sensibitiles looking at old media with their own cultural expectations, rather than the ones in place when it was created.
Of course that doesn't prevent the word from possibly having come from there. But it seems more likely as a modern myth for the word's origin than as an actual possible etymology.