Magpie is a female super criminal in Beware The Batman. She debuted in the episode "Secrets". Magpie suffers from a dissociative identity disorder and exhibits multiple personalities.
Magpie's true name is Margaret Sorrow. She was a chronic kleptomaniac and inmate at Black Gate Prison. While serving her time in the prison, she took part in experiments in mind manipulation conducted by Joe Braxton and Bethany Ravencroft. They used a helmet-like device on her to wipe away her original memories, removing the criminal aspects of her personality. She was given a new face and a new name; Cassie.
However, the removed aspects of Sorrow's original personality were not actually gone, and instead deeply buried in her subconscious, eventually resurfacing in the form of Magpie. Not knowing who her true self was, Magpie vowed to make Braxton and Ravencroft pay for what they did to her and get her stolen life back. As Cassie, Magpie got work as Dr. Ravencroft's receptionist, possibly driven there subconsciously by Magpie in order to get close to Ravencroft in order to enact her revenge.
In her first on-screen appearance, Magpie attacks Braxton and successfully wipes his memories, catching the attention of Batman. Magpie attempts to goad Batman, declaring that they're very much alike due to the dark design of their costumes. Eventually, in her attempt to force Ravencroft to restore her memories, Batman reveals her past as Margaret Sorrow. Unable to recognize her other personality Cassie or reconcile with her criminal past, Magpie lashes out at Batman but is eventually subdued and arrested.
In Attraction, Magpie is revealed to have developed a romantic obsession with Batman, due to Batman secretly visiting her at Blackgate. Unknown to her, Batman empathized with how Magpie never received the psychiatric help she needed. Upon seeing Katana at Batman's side, Magpie believes that the two are romantically involved and resolves to kill Katana, so she can have Batman all to herself. Magpie is angered when Batman rebuffs her advances, and has Katana kidnapped to be buried alive. However, both Batman and Katana break out and defeat Magpie.
Magpie made a small appearance in Reckoning, where Ra's al Ghul frees her and other villains from Blackgate Penitentiary, where he promised them a portion of Gotham City to rule if they brought Batman to him. Magpie was the second one who tried to capture Batman, but she was stopped by Phosphorus Rex, who also tried to capture Batman. Magpie and Phosphorus Rex fell in battle, and became mind controlled by Cypher, but Batman quickly freed them. Magpie later engaged in a brawl to take Batman in, allowing the hero to slip away as the villains fought each other.
During the day she is a perfectly normal-looking young woman named Margaret sorrow with a fake name called Cassie with short cropped hair and grey eyes. She wears a black sleeveless shirt and a beige knee-length skirt when working as a receptionist. At night as Magpie she wears a white, shoulder length wig and black make-up around her eyes. She also sports a black leather outfit with feathery wing-like ornaments on her shoulders and wears black thigh-high heeled leather boots. Her fingernails can sprout into long razor sharp talons lined with the nerve poison curare, which she uses as her primary weapons. She is an extremely quick and agile fighter, easily keeping up with Batman. The experiments on her mind had the side effect of making her immune to pain, so she is much more durable than she appears and is able to ignore most injuries. She retains her original kleptomania and can't resist taking things that shine and sparkle much like her namesake.