Mary Dahl grew up with a systemic Hypoplasia condition , that halted her body growth. As a result, she has not grown larger physically since her fifth birthday. However, other factors, such as intellectual development, did proceed normally, and Dahl apparently went through puberty, as when not in her "Baby Doll" persona she was speaking in a deeper feminine voice akin to a full-grown woman's
Years later she became an actress and got the lead role in a comedy series called "Love That Baby", where she shared the spotlight with actors like Tod Baker, June Winthrop, Brian Daly, and Tammy Vance, who respectively played a family Father, Mother and the older brother and sister Tippy and Susie. Mary Dahl herself played Baby-Doll, who was adored on the screen due to her mischievous antics and her cutesy "I didn't mean to" defense. However, the early success got to Dahl, where she gained the reputation as a diva and difficult to work with the crew and other actors. The show was a hit for a couple of years, but when ratings started to drop, the directors added a new member to the cast, Baby-Doll's cousin Spunky. When the young actor started to out stage Mary Dahl at Baby-Doll's birthday episode, she left the show claiming she did not get enough exposure, causing the show to be canceled. Unknown to her, she threw away the high point of her life. Mary Dahl decided to study drama and become a dramatic actress. When she starred as Lady MacBeth in a stage production of MacBeth, her performance was panned. When she attempted to revive "Love That Baby", the studios turned her down. Mary Dahl had no choice but to put an end to her acting career, and she seemed to fade away.
10 years later, Tod Baker, June Winthrop, and Brian Daly, the old cast members of "Love That Baby" started to disappear. The Gotham City Police Department were deployed to guard and protect the remaining actress Tammy Vance. The Dynamic Duo almost captured the culprit, the star of the "Love That Baby" cast Mary Louise Dahl. But even their timely arrival could not prevent Tammy Vance's abduction.
Mary Dahl had decided to live in a world of make-believe, taking "Baby-Doll" as her persona from now on. The abductions were an attempt to revive her "family" and star in the series once more, whether the rest liked it or not, and had personal bodyguards surrounding the sets to prevent them from escaping, including a woman named Miriam who posed as her mother whenever the two of them went out anywhere. She eventually had the actor who played Spunky kidnapped and forced to blow out birthday candles with a stick of dynamite among them. The actor turned out to be Robin in disguise, who took the actor's place and hurled the stick of dynamite off the set with his teeth while Batman took down the bodyguards. As Robin freed the actors held hostage, Batman chased Mary Dahl to a carnival's fun house, where she saw in one of its mirrors a reflection of what she might have looked like in an adult body. Realizing that the reflection was no more real than the TV family life she tried to recreate, Mary Dahl destroyed the mirror and humbly surrendered herself to Batman with a rather mournful and womanly "I didn't mean to".
Some years later, with her sanity partially restored, Mary tried to get gainful employment working in obscurity as a hotel manager, but a brutal encounter with an insensitive fan of "Love That Baby" got her nearly fired, after the fan harassed her. Returning home to her apartment in frustration, she watches as Killer Croc gets into a brawl during a televised court hearing, feeling empathy for his situation of being a physical outcast. She visits him in his prison cell to offer him an escape in exchange for a partnership, and engineers it by appearing in front of a transport truck as an innocent child about to be run over, causing the drivers to pull off over the edge of the road, toppling the truck. From that point, Killer Croc and Baby Doll went on crime sprees together throughout Gotham City, keeping the likes of Batman at bay. However, Killer Croc did not like the nature of his relationship with Mary Dahl, whom he saw as a perpetual child, and cheated on her behind her back. This caused Mary to decide to blow the both of them up at Gotham's Nuclear Power Plant, but she was foiled by Batman and Batgirl.
- Acting: As an actress, Mary was able to blend in with a crowd of children, or cry and make people feel sorry for her.
- Stunted Growth: Mary Dahl has the strength and body of a 5 year old due to her systemic Hypoplasia condition.
- Tommy Gun: A tommy gun that was hidden inside her rag doll, and a toy gun with suction cup projectiles that emitted painful electrical jolts.
- Baby-Doll was voiced by Alison La Placa for the episode "Baby-Doll" and Laraine Newman for "Love is a Croc".
- 3 Appearances of Mary Dahl (DCAU)
- 5 Images featuring Mary Dahl (DCAU)
- 3 Quotations by or about Mary Dahl (DCAU)
- Character Gallery: Mary Dahl (DCAU)