She is the supreme commander of Hydra. Madame Hydra, she took control of Hydra's New York branch, and from there the rest of it. Viper is a master of poisons, and is immune to almost all toxins. In fact, she uses a poisonous lipstick to give her foes a literal "kiss of death,".

She is the one who originally sponsored the creation of X23 with her scientist Deborah Risman. She uses grunts like Gauntlet and Omega Red to do her dirty work, but like a true bully, once cornered she panics. X23 was finally able to trap her aboard a hover craft, which she then destroyed. Whether Viper survived the crash or not is unknown.