Gotham's most wanted list continues to grow with the addition of supervillain Mr. Freeze, who will join the cast on the upcoming Fox series later this season.

"You will see Mr. Freeze on the streets of #Gotham. And when you do, we urge you to cross the other side," 'Gotham' tweeted on Aug. 5.

Detectives James Gordon and Harvey Bullock have enough problems with the sadistic crime boss Fish Mooney and her minions Oswald Cobblepot (the future Penguin) and Selina Kyle (the future Catwoman) stirring up trouble. Like Cobblepot and Kyle, Freeze will get his own origin story, and executive producer Danny Cannon has the perfect one in mind, thanks to his work on CSI.

"Without giving too much away - because I'm not allowed to - the great thing about working on a CSI procedural show for so long was that we worked with many experts - specialists in each field," he told Digital Spy. "There's a lot of things I pick up along the way."

He spoke with showrunner Bruno Heller about their villains and keeping the story credible and relatable, especially when it comes to the science.

"So I had a couple of stories that I'd held onto - real, true stories - and one of them just related to Mr. Freeze. I know a real way to create an origin story."

A new teaser trailer reveals more of Fish Mooney's story and what the sexy, wicked woman hopes to accomplish in Gotham.

"Somebody has to take over, might as well be me," says Mooney, the gangster boss and nightclub owner. She carries a baseball bat, which she doesn't hesitate to use, and has her thugs kidnap Det. Gordon (Ben McKenzie).

A longer version of the Mooney trailer will air tonight during Fox's "So You Think You Can Dance" at 8 p.m.