"Gotham" cast line-up is expanding. The Batman prequel series has tapped more actors in key roles, including notable villain The Penguin and Bruce Wayne's butler Alfred Pennyworth, after casting Benjamin McKenzie as the central character, Detective James Gordon, AceShowbiz said.

Robin Lord Taylor ("Accepted", "The Walking Dead") joins the cast as Oswald Cobblepot a.k.a. The Penguin. Described as having "the brains of a chess grandmaster and the morals of a jackal," he "is a low-level psychopath for gangster Fish Mooney who hides his sadistic lust for power behind an exquisitely polite demeanor."

Alfred will be portrayed by Sean Pertwee ("Elementary", "Camelot"). The iconic butler is "a tough-as-nails ex-Marine from East London who has loyally served Thomas and Martha Wayne for years. Now, in the wake of their tragic deaths, he is fiercely protective of their young son, Bruce."

Zabryna Guevara ("Burn Notice") is cast as Captain Essen, Gordon's boss at the GCPD Homicide Squad who "balances the two worlds of police and politics with a Machiavellian skill that's as much corporate litigator as cop."

Erin Richards ("Being Human", "Breaking In") lands the role of Barbara Kean, "a sophisticated emergency room doctor" who is engaged to Gordon. "Joyful but with an edge of vulnerability, she stands by her future husband which can be difficult in a world as corrupt as Gotham."

"Gotham" will explore the origin stories of Commissioner James Gordon. "The Mentalist" creator Bruno Heller is writing the pilot while Danny Cannon ("CSI: Crime Scene Investigation", "Nikita") is on board to direct and executive produce the pilot. More familiar faces such as the Joker, the Riddler and Catwoman are expected to be featured on the prequel series.