Poison Ivy

Dr. Pamela Lillian Isley was a botanist from Seattle. After an attempted poisoning by one of her colleagues she was rushed to a hospital. The plant-based toxin didn't kill her, however the chemicals altered her DNA, driving her insane and forming an immunity to naturally occurring poisons and diseases.

She later relocated to Gotham, where she assumed the alter-ego Poison Ivy, an Eco-terrorist bent on human annihilation.