Since childhood, Charlene had been fascinated by serpents. She began to keep them as pets as a young girl, leading to her ostracism from her peers. She compensated for her vilification by isolating herself even further, spending all her time with her pets. She grew to be a beautiful young woman, but totally alienated. She turned her avocation to her vocation, taking a job as a snake charmer in a side show.
One advantage of her occupation was Charlene was able to visit nearby towns while the show was on tour. One day, in middle Europe, she happened across a curious trinket in a curio shop. It was a small statue depicting a creature with a woman's torso and with a snake's tail. She purchased it to decorate her quarters. Over the next month she studied it carefully, trying to discover its origins. She returned to her quarters one night to find the full moon shining through the eyes of the statue, causing them to glow. Charlene knelt before the statue, unconsciously emulating its pose. As the light from the statue bathed her, she began to hear voices, whispering, telling her what to do. As if in answer to her prayers, Charlene began to change. Her canine teeth extended to become fangs, her tongue bifurcated, and her legs lengthened and fused to form a prehensile tail. Charlene was no more. She had become Lady Viper, the queen of the serpents.
She found she could hypnotize men with her sibilant voice and uncanny stare. She also found she'd gained superhuman strength, due to the additional muscle mass of her tail. A side effect of the metamorphosis was that the longer Lady Viper remained in that form, the more snake-like she became. As Lady Viper, she set out to gain all the wealth and milieu that had been denied her. Unfortunately, her nocturnal thefts attracted Batgirl's attention. She was able to overpower Batgirl and, overcome by the thrill, bit her on the neck. Batgirl managed to escape and injected herself with antitoxin before collapsing in an alley. Lady Viper assumed Batgirl died from her attack.
Lady Viper assumed incorrectly. Batgirl, in a fever-dream, battled Lady Viper again. This time they battled on equal terms, as Batgirl also possessed a serpent's tail. However, when Batgirl awoke she discovered her nightmare was true: she had become another snake-woman. To her relief, Barbara found that by concentrating she was able revert temporarily to human form. She took time out to have an experimental antivenin developed from a blood sample, then returned to the hunt for Lady Viper. Once she found her, Batgirl engaged Lady Viper again. Barbara surprised the villainess a second time by transforming to her snake form. In that form, she was able to fight Lady Viper to a draw and managed to knocked her out. Once Charlene was out cold Barbara was able to extract a sample of her venom. Although the unliving voices tempted Barbara to keep her snake powers she took the anti-venom. Once cured she returned for Charlene who had just regained consciousness. However Charlene remained too long in her serpent form, and started turning completely into an enormous snake to Batgirls horror. With her last trace of humanity she cursed Batgirl for what happened to her. Now nothing more than a mindless reptile Barbara arranged for Charlene and her pets to be kept at the Gotham zoo.