Stories We Like: A Guide to the Comma
"timid, meek person," 1938, from Caspar Milquetoast, character created by U.S. newspaper cartoonist H.T. Webster (1885-1952) in the strip "The Timid Soul," which ran from 1924 in the "New York World" and later the "Herald Tribune." By 1930 the name was being referenced as a type of the meek man. The form seems to be milktoast with an added French twist; cf. also milksop.
A mild, ineffectual person; a timid person; wimp
[1924+; fr or popularized by the comic-strip character Caspar Milquetoast in ''The Timid Soul'' by H T Webster]