- DC: "what if... Barbara Gordon became the Man-bat" (Batman: The Animated Series 1992) [given by 3mtsims AO3]
Batman was worried, that was a rare thing, but this had him worried, Joker had heard about the mutating formula from Gotham Zoo, had broken into and taken the old research the family had locked away after the two incidents, while he would have preferred it destroyed he understood how such research could help the deaf, he should have made a proper vault for them to store it in, but he couldn't dwell on such things now, he and Robin where to meet Batgirl at the Jokers hideout and hopefully stop him before it was too late.
Little did he know Batgirl had already arrived and was sneaking around, she soon found Joker working while he chuckled madly, she would have watched longer had she not needed to jump away from Harley's mallet that dented the railings, after a few moments of dodging she hit Harley off and down onto table some thugs where playing cards at, she soon followed down ready for a fight.
Joker made his big show of how he wanted the bat to show first but a pre-performance wouldn't be unwanted, that's when he took a syringe and injected a nearby thug, and in seconds he mutated into a man-bat, that's when Batman and Robin burst through the skylight, grinning the Joker monologues about him being a little late and that this was one of his best jokes, to have Gotham, that was protected by the bat, destroyed by bat monsters, that's when the new man-bat went on the attack and Joker injected the remaining formula into three other thugs before he and Harley made their escape.
The bat team fought against the mutants, being able to take two down before the other two fled into the sky, leaving the bats with the remaining thugs, Batgirl told the pair to go after the mutants while she handled the thugs, and with that they split up. Batgirl handled the thugs with ease and soon they were knocked out, but that's when one of the downed man-bats got back up and swiped her back drawing blood, Batgirl went on to fight it but during the fight, she started getting hot and her body twitched in pain.
Batman and Robin arrived back with their mutants in time to watch as Batgirl turned into a female Man-bat and continued fighting the other man-bat, Batman jumped down to the Joker's workbench and quickly went over the details, finding that he had used a mi of the mutant formula and Bane's venom, altering so the mutation can pass onto others from injury, like a werewolf. That is when Batgirl flung the man-bat into the wall, knocking it out for good, she then began to advance on the heroes before Batman threw sonic pellets that messed up her hearing and then hit her with a stun dart, the pair then loaded the mutants and the research, returning to the Batcave.
Curing the thugs was easy, however, Batgirl wasn't, having been exposed to other chemicals in their line of work and being mutated from a man-bat instead of injected had left complications, they were able to return her to human form, but she was now alter permanently, able to shift between human and girl-bat at will or partly, while a little upset at the Joker getting a partial win Barbra was slightly happy to have some powers and able to fly under her own power. They helped her train with her new abilities and alter her clothing so it altered form with her transformations, new tools that she can use with her normal hands and limited digits in bat form, in the end, it wasn't too big a change but opened up new doors for them with her abilities ranging from flight, super hearing, claws and even a sonic screech, even Supergirl came to like them as she got to fly around with her friend.