After watching 28 episodes of Gotham so far (22 first season, 6 second season), I have fallen in love with the concept. Robin Lord-Taylor's portrayal of Oswald Cobblepot as he transforms into The Penguin is amazing, Cory Michael Smith makes a delightfully quirky Edward Nygma, and Ben McKenzie has shown that James Gordon is definitely in over his head, with only more problems to come.
However, as I re-watched Season 1 of Gotham, I realized that this was the only time I had ever heard of characters like The Balloon Man and The Spirit of the Goat. Are these two characters in any previous canon, perhaps Batman: The Animated Series, or possibly one-shot villains from the comics?
After all, I know that Fish Mooney was created to advance Penguin's storyline, but I just wasn't sure about these other two. Any help would be greatly appreciated.