Rosie O'Gravy is the chief of detectives on the animated portions of Dog City. Voiced by Elizabeth Hanna, Rosie is an attractive but 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 warrants it.
Rosie's creator Eliot Shag often uses her to work out his own feelings about his girlfriends, Colleen Barker (who Rosie resembles physically) and Terri Springer.