Noting that hundreds of Internet RFCs "contain the terms `foo', `bar', or `foobar' as metasyntactic variables without any proper explanation or definition," this old April Fools RFC examines the roots of Foo, Bar and fubar.
For, it seems, the word `foo' itself had an immediate prewar
history in comic strips and cartoons. In the 1938 Warner Brothers
cartoon directed by Robert Clampett, "The Daffy Doc", a very early
version of Daffy Duck holds up a sign saying "SILENCE IS FOO!"
`FOO' and `BAR' also occurred in Walt Kelly's "Pogo" strips. The
earliest documented uses were in the surrealist "Smokey Stover"
comic strip by Bill Holman about a fireman. This comic strip
appeared in various American comics including "Everybody's"
between about 1930 and 1952. It frequently included the word
"FOO" on license plates of cars, in nonsense sayings in the
background of some frames such as "He who foos last foos best" or
"Many smoke but foo men chew", and had Smokey say "Where there's
foo, there's fire". Bill Holman, the author of the strip, filled
it with odd jokes and personal contrivances, including other
(via JWZ)
