Biography
A specific type of itinerant Con Man who makes his living by selling products which could not possibly work as advertised. The classic version sells literal snake oil (i.e. a product with 'medicinal' properties and exotic, unknown ingredients). A minor variation on this character is the Rainmaker, who takes people's money under the pretense that they will do something that they have no ability to do, such as making it rain.
This shady dealer is somewhat similar to the Hustler in being both less financially stable and having a poorer group of victims as well, and also has some overlap with the Honest John as being a purveyor of shoddy goods, not always phony medicine.
The character is often played as a Loveable Rogue, frequently being extremely attractive to local women because he's "seen the world" (or at least can convincingly pretend that he has). He's often inexplicably sympathetic, given that he makes his money hawking fake medicine for genuine ailments — though the audience will generally be less sympathetic if he's got a big, professional-looking operation, especially if he uses shills and/or he clearly knows his cures are bogus.
Definitely Truth in Television, hearkening back to the late-19th/early-20th century, when there were no standards for practicing medicine or selling goods and "caveat emptor"note was the rule. The rise of "alternative medicine" and other forms of All-Natural Snake Oil provides lots of modern examples as well, as do online scams (think of ads along the lines of "doctors hate this man who cured X with one weird trick!"). A Snake Oil Salesman is also known as a "quack", short for "quacksalver", though the term "quack" also covers fraudulent doctors who are nowhere near as skilled as they claim to be, such as the worst Back Alley Doctors. Any beneficial results given by the "medicine" are almost certainly down to the Placebo Effect.
In an interesting subversion, actual snake oil contains plenty of Omega-3, which has known therapeutic effects. However, in a Double Subversion, the actual benefits are so vague to laymen that the modern version of this could be "Fish Oil" or "Omega-3 Salesman". Also, oil from the Chinese Water Snake has been used for a very long time in Chinese medicine, though not as the extreme panacea advertised by this sort of character (indeed, this connotation is largely unknown in Chinanote ). Rather, it's merely used as an ordinary anti-inflammatory agent, originally introduced into the United States by Chinese railroad workers. The modern definition originated with Clark Stanley, a Texas businessman who claimed to have received Hopi knowledge about the medicinal properties of rattlesnake oil — as it turns out, his medicine contained virtually no such oil, and in 1989 it was established that real rattlesnake oil contained only one-third of the Omega-3 content of their Chinese counterparts.
Similar to the Fake Faith Healer, but without the religious overtones.
Expect to find actual Snake Oil Salesmen at the local Medicine Show.
NB: To count as an example, the Snake Oil Salesman has to be knowingly hawking fake medicine. Well-intentioned ignorance fits better under Worst Aid.