Origin

Mary Dahl was born with a rare disorder which caused her to never grow beyond that of a toddler. But her mind did advance just as any other person would and she became an actress. She was the star in the television sitcom Baby Doll and was very successful. However, the series eventually dwindled in popularity and she left the show after she felt she was being overshadowed by a new character added to boost ratings.

She tried to continue her acting career but her physical appearance held her back from great success. Additionally, having to forever be in the body of a child weighed on her mental condition as she could not have normal relationships.

Creation

Baby Doll was created by Paul Dini for Batman: The Animated Series. She first appeared in the episode Baby Doll.

Major Story Arcs

Baby Doll began her criminal career by kidnapping the original cast of her television show, wanting her family back so she could be happy again. She also planned to kill the actor who caused her to leave the show. She was thwarted by Batman and Robin.

Later, she attempted to have a normal life and got a job but became infatuated with Killer Croc. She felt he was a kindred spirit in that he was an outcast and together they started criminal activities. But once Baby Doll found out that Croc did not share her feelings, she attempted to kill him and herself along with Gotham City by blowing up a nuclear power plant. She was once again stopped by Batman and Batgirl and taken into custody.

Batman: White Knight

Baby Doll can be seen with other villains like Killer Croc, Ventriloquist and others under Jack Napier's mind control using Mad Hatter's tech to rampage in the the poor Backport District. How much of her history, if any, is similar to her story in the animated series is unknown.

Other Media

Batman Animated Series

Baby Boom's origin was later revamped by the Batman Animated Series. Baby Boom was renamed as Baby Doll and her ability to explode anything with her mind was dismissed entirely.

After Mary's failed attempt at achieving her former fame and glory, she was put through a rehabilitation program at Arkham and was released a year later. The Wayne Foundation gave Mary a steady form of employment by making her an innkeeper at one of Gotham's romantic getaway spots. Unfortunately, Mary's alter ego was beginning to settle back in when a tenant at the inn harassed her about her former life as an actress. Mary's sanity takes an even deeper plunge when she falls for the sob story that Killer Croc was giving during his sentence hearing.