"Supergirl" has added another Supergirl to the mix: Laura Vandervoort, who played Kara Zor-El/Supergirl from 2007 to 2011 on "Smallville," has been cast as Indigo, a recurring role on the CBS series, as announced Monday by Warner Bros. Television at the Television Critics Association Winter Press Tour.

Here's the official description of Indigo: "A living, strong-willed supercomputer that was sentenced to Fort Rozz after turning against the people of Krypton. Now on Earth, Indigo will let nothing stand in her way."

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Additionally, Jeff Branson has been cast as Master Jailer, in another recurring role. Here's the description: "As the forceful and unrelenting jail guard on Fort Rozz, Master Jailer showed no mercy. Now on Earth, he is hellbent on catching all of the Fort Rozz escapees and brutally bringing them to justice."

Both characters have roots in DC Comics history. Indigo was created by Judd Winick and Ale Garza, and first appeared in 2003's "Titans/Young Justice: Graduation Day" #1. Indigo was a main character in the subsequent "Outsiders" team book.

Master Jailer has a longer history at DC, dating back to 1979's "Superman" #331. Created by Martin Pasko and Curt Swan, the character has also been known as Kator and Deathtrap.

This isn't the first time "Supergirl" has cast a performer with ties to a previous Superman-related show or film. Helen Slater, who starred in the 1984 "Supergirl" film, and Dean Cain, the Man of Steel of "Lois & Clark: The New Adventures of Superman," have appeared on the series as Kara's (Melissa Benoist) foster parents, Eliza and Jeremiah Danvers.

"Supergirl" airs Mondays at 8 p.m. on CBS.