Although the film was publicized as the first screen pairing of Warner Bros.' two biggest stars, Bette Davis and James Cagney had actually made this 1934 film together.
"Taxi!" is an earlier instance of James Cagney playing a character who calls somebody a "dirty rat." In "Taxi!" it's "dirty, yellow-bellied rat." In "Jimmy The Gent," it's "dirty, little rat."