While still a young child, Rebecca fell deathly ill from a mysterious disease. Batman tried to help the Langstroms, but when he came into possession of the Seronotal needed to save her life, the Batman destroyed it, believing the formula had been tainted.
Rebecca was eventually saved, due in no small part to the efforts of Superman, but Kirk felt that Batman had betrayed them and had tried to kill his daughter. His hatred of Batman grew into an obsession and this obsession began to affect his work. In short order, the Langstroms lost their home and their fortune. They were forced to return to Gotham City where they lived in a rundown apartment in Gotham's East End.
Rebecca developed an illness due to her enhanced hearing sense, which didn't allow her to sleep. Her father tried to use an experimental illegal drug on her, but Batman prevented this, forcing Rebecca to remain with her illness longer than necessary, although he did it to save her life. Man-Bat eventually crossed paths with Superman, who helped him and found a cure for Rebecca.
Unfortunately, Rebecca's father overdosed on the Man-Bat Serum and in his crazed state, he believed that Rebecca was dead. He blamed Batman for her death and they clashed a couple of times, before Batman took Rebecca with him to confront Man-Bat. At the sight of his daughter, Man-Bat recovered some of his consciousness, which allowed Batman to inject him with a more powerful antidote to revert the transformation. When her father had a relapse, Rebecca and her mother assisted Batman in order to help her father and revert the transformation one more time.
- Enhanced Hearing: Rebecca inherited a superior hearing sense from her father's abilities while transformed as Man-Bat
- Although this character was originally introduced during DC's Earth-One era of publication, their existence following the events of the 1985–86 limited series Crisis on Infinite Earths remains intact. However, some elements of the character's Pre-Crisis history may have been altered or removed for Post-Crisis New Earth continuity, and should be considered apocryphal.
- 22 Appearances of Rebecca Langstrom (New Earth)
- 2 Images featuring Rebecca Langstrom (New Earth)
- Quotations by or about Rebecca Langstrom (New Earth)
- Character Gallery: Rebecca Langstrom (New Earth)