In the fictional universe of the Batman comic book series, Harvey Bullock is a police detective in the Gotham City Police Department. In most versions of the story, Bullock is a gruff, overweight, somewhat slovenly fellow, noted for his hard drinking, belligerent demeanor, and trademark fedora and trench coat, but who also has a hidden sentimental side that peeks out on rare occasions. He is generally a good cop, although he doesn't always play by the books and is perhaps a bit too quick to use violence and intimidation to get his way when detection alone proves insufficient.
Bullock was actually created by legendary comic book writer Archie Goodwin, and made his first appearance in Detective Comics #441 (June 1974). In his initial incarnation, Bullock was actually a corrupt cop working in cahoots with corrupt Gotham City mayor Hamilton Hill to bring down Commissioner Gordon from within, but all later incarnations of Bullock have portrayed him more as a sheep in wolf's clothing, with a common storyline having him being accused or suspected of corruption or misdeeds, but in the end having him wind up exonerated of wrongdoing.
Perhaps the most prominent portrayal of Harvey Bullock, which most fans remember best, was in the 1990s cartoon Batman: The Animated Series, in which Bullock was made one of the major recurring characters and was even the star or co-star of several episodes.