The nearly indigent "free lunch fiend" was a recognized social type. An 1872 New York Times story about "loafers and free-lunch men" who "toil not, neither do they spin, yet they 'get along'", visiting saloons, trying to bum drinks from strangers: "Should this inexplicable lunch-fiend not happen to be called to drink, he devours whatever he can, and, while the bartender is occupied, tries to escape unnoticed."
FreeLunchFiend sounds like a fun username.