Update! 

According to Comicbook.com, Flanagan will play a new character called the Knife. “The Knife is one of Gotham’s most dangerous denizens. His charming, stylish shell and good humor mask a remorseless hitman whose skills are at the service of the highest bidder. He will sit with you, laugh with you, and then cut your throat.” Flanagan will make his debut in the 10th episode of the second season.

Squeee!! ‘Sons of Anarchy‘ alum Tommy Flanagan will guest-star in Season 2 of ‘Gotham.’ Flanagan took to Twitter to make the announcement, saying,”I’m on the next flight to @gotham Send the #Batmobile. I’m driving. #IAintNoJoker @FOXTV #gotham #FOX #Batman.”

Details on his role are still under wraps.

“I’m on the next flight to @gotham Send the #Batmobile. I’m driving. #IAintNoJoker @FOXTV #gotham #FOX #Batman”

Official Description:

Penguin is King of Gotham and after a shakeup at the GCPD, Detective James Gordon’s moral compass wavers, as he seeks help from Penguin. Meanwhile, Bruce Wayne continues to explore the secrets from his father’s office, while GOTHAM newcomers Theo Galavan (James Frain) and his sister, Tabitha (Jessica Lucas), make friends with some unlikely allies, a group of dangerous inmates from Arkham in the all-new “Rise of the Villains: Damned If You Do,…”

Season Two premiere episode of GOTHAM airing Monday, Sept. 21 (8:00-9:00 PM ET/PT) on FOX. (GTH-201) (TV-14 L, S, V) Cast: Ben McKenzie as Detective James Gordon, Donal Logue as Harvey Bullock, Michael Chiklis as Detective Nathaniel Barnes, Sean Pertwee as Alfred, Robin Lord Taylor as Oswald Cobblepot/The Penguin, Erin Richards as Barbara Kean, David Mazouz as Bruce Wayne, Camren Bicondova as Selina Kyle/the future Catwoman, Cory Michael Smith as Edward Nygma/the future Riddler, James Frain as Theo Galavan, Jessica Lucas as Tabitha Galavan, Chris Chalk as Lucius Fox, Nicholas D’Agosto as Harvey Dent, Zabryna Guevara as Captain Sarah Essen

Guest Cast: Drew Powell as Butch Gilzean, Peter Scolari as Commissioner Loeb, Anthony Carrigan as Victor Zsasz, James Andrew O’Connor as Tommy Bones, David Fierro as Zaardon, Cameron Monaghan as Jerome, Todd Stashwick as Richard Sionis, Will Brill as Arnold Dobkins, Stink Fisher as Aaron Helzinger, Dustin Ybarra as Robert Greenwood, Otto Sanchez as Odgen Barker, Philip Goodwin as Compere

‘Gotham’ airs Monday at 8:00 PM ET/PT on FOX.