Passepartout is the name of Phileas Fogg's companion (actually his valet) in Jules Verne's book Around the World in Eighty Days. It comes from the French "passe partout" which means "able to go anywhere". Verne describes Passepartout as having "a pleasant face, lips a trifle protruding, soft-mannered and serviceable, with a good round head, such as one likes to see on the shoulders of a friend". Passepartout is characterized by his unwavering loyalty to Fogg, a man he only meets the day before their trip. Although in America, Passepartout and Fogg (and the detective Fix) get separated.
Before I took French in Junior High School, I mistakenly thought that Passepartout was a play-on-words on "passport".