The subtitle of Gotham Season 2 was Rise of the Villains, and it has certainly lived up to that throughout the season. The Fox series has not only developed its villainous characters from its first season – like The Riddler and The Penguin - it’s also introduced a bunch from Batman's rogues gallery, including Hugo Strange, Mr. Freeze, Firefly, Azrael, and Clayface.
You can rest assured that another set of Batman villains are in the pipeline for the coming season. And now, we know some of their names. That's because John Stephens, one of Gotham’s executive producers, has confirmed certain baddies for the show’s Third Season.
In a recent interview with Comic Book Resources, the EP says:
We’ll be seeing Mad Hatter in Season 3. We’ll be seeing the Tweedle Brothers, too, if we’re going to bring the Hatter in. In line with the Court of Owls, we’ll be seeing Talon. And we should be seeing Solomon Grundy.
The show actually had plans to add Dr. Jervis Tetch, aka Mad Hatter, during the second half of the second season. The EP had previously teased the character’s appearance. But for some reason, they have decided to push back his arrival in Gotham.
Tweedledum and Tweedledee haven't been teased on the series yet. However, the supervillain duo has worked with Mad Hatter in the comics. So, we wouldn't be surprised if they teamed up in Gotham Season 3, too.
We already know that Court of Owls exists in the series. Since Talon is a member of the organized crime group, bringing him in seems a pretty obvious choice.
Solomon Grundy is the only one among these characters who isn't a genuine Batman villain. He was introduced as a Green Lantern nemesis back in the 1940s. However, he crossed paths with numerous DC Comics superheroes later on, the Caped Crusader among them. The zombie supervillain has also had brief appearances in recent television shows, including Smallville and Arrow.