- You may also be looking for the episode "Baby-Doll"
Baby-Doll was an ex-actress-turned-villainess.
Mary Dahl was an actress and the star of TV program, Love that Baby, a famed TV sitcom made at Gotham Studios, as the character Baby Doll. Throughout her life she suffered from systemic hypoplasia, an extremely rare medical condition that prevented her body from physically aging (in her case, she stopped growing past the age of 5)--so even though she looked like a little kid, she was actually an adult. She also went through puberty because although she did not grow taller, her natural voice was that of a grown woman, and not that of her "Baby Doll" persona. In the last season of the series, Dahl complained she wasn't getting enough exposure and abruptly quit. After leaving the show, she studied drama and trained to become a dramatic actress. Her first and only job as a dramatic actress was in a rendition of Macbeth, which was given a "P.U." by the critics. Sometime after this, she attempted to revive Love That Baby and the studios turned her down. For 10 years, Dahl lived as a recluse.
Upon her 30th birthday, Mary's mind snapped. She started to act like, dress like, and even talk like and called herself Baby-Doll. With the help of her hired henchmen and her right hand woman, Mariam, she kidnapped the former cast members in a convoluted attempt to restore her old TV-family, a time when she was happy. She even carried around a tape recorder to recreate the studio audience. She also intended to capture the main cast member from her last season, "Cousin Spunky," and torment and kill him in revenge for stealing the limelight from her. She also intended to blow up the cast with a cake rigged with dynamite, and intended for herself to be among the deaths. In an unguarded moment, she spoke in her real voice and admitted to how lonely she'd been after the show; then she snapped right back to "Baby Doll".
Batman and Robin intervened, with Robin switching places with Spunky Spencer and carrying a homing transmitter. After he was captured, Batman was able to locate Doll's hideout. After attempting to kill Batman, Baby-Doll escaped to a nearby amusement park. During the pursuit, she ended up in the house of mirrors and saw herself in a mirror, resembling how she might have looked as an adult if not for her condition. Her knowledge that this was fake forced her to realize that her "family" was fake too. Breaking down in the face of reality, she destroyed every mirror with her firearm before losing all will to fight and crying for the life she'll never have.
Return to Crime
Some time after this incident, Dahl had apparently been rehabilitated. She seemed to have adjusted to life as a grown woman (as best possible) and got a job as a front desk agent in a Gotham City motel, which also included live-in residence. A drunken guest identified her and pried her about her hypoplasia. Dahl gave a simple answer, but when the man invaded her personal space, rudely spoke of her crime and then asked her to "do something funny" she snapped, then withdrew to her room and turned on the TV. While watching a news segment on Killer Croc's latest court appearance, Doll empathized with Croc, as she believed both of them were kindred spirits, misunderstood, "different" and shunned by society. While being transferred from Arkham to State Prison, Croc was freed by Doll who staged numerous thefts near water to play up the strategic advantage.
Meanwhile, Croc planned to leave Gotham with all the stolen gains and without Dahl, who found this out and planned one last heist at Mid-River Island. She secretly planned to sabotage the Island's nuclear power plant and level Gotham and its inhabitants, including Croc and herself. However, Batman and Batgirl intervened to halt the countdown and subdued Croc before he could kill Doll. She mourned his betrayal of her, sadly saying that they could have been happy.