Rosie O'Gravy is the chief of detectives on the animated segments of the Dog City television series. Rosie is an attractive, independent-minded collie and an effective, if by the book, officer. Chief Rosie and Ace Hart exchange witty barbs in the best film noir tradition, and romantic sparks often fly. However, Rosie's still a police dog and, despite her personal feelings, won't hesitate to bust even Ace if the situation and the law warrant it.