Poison Ivy is an enemy of Batman. She is depicted as one of the world's most prominent eco-terrorists. She is obsessed with plants, botany, and environmentalism. She uses toxins from plants and her own bloodstream for her criminal activities, which are usually aimed at protecting the natural environment. She creates love potions that ensnare Batman, Superman, and other strong-willed individuals. Fellow villain Harley Quinn is her recurring partner-in-crime and possibly her only human friend.
Pre-Crisis, Dr. Pamela Lillian Isley, a promising botanist from Seattle, was seduced by her high school professor Marc LeGrande into assisting him with the theft of an Egyptian artifact containing ancient herbs. Fearing she would implicate him in the theft, he attempts to poison her with the herbs, which are deadly and untraceable. She survives this murder attempt and discovers she has acquired an immunity to all natural toxins and diseases.
Following the merging of realities during the cosmic event known as the Crisis on Infinite Earths, her origins were revised. Pamela Isley grows up wealthy with emotionally distant parents. She later studies advanced botanical biochemistry at a university with Alec Holland under Dr. Jason Woodrue. Isley, a timid, shrinking violet, is easily seduced by her professor. Woodrue injects Isley with poisons and toxins as an experiment, causing her transformation. She nearly dies twice as a result from these poisonings, driving her insane. Later Woodrue flees from the authorities, leaving Pamela in the hospital for six months. Enraged at the betrayal, Pamela suffers from violent mood swings, being sweet one moment and like poison the next. When her boyfriend has a car accident after mysteriously suffering from a massive fungal overgrowth, Isley drops out of school and leaves Seattle, eventually settling in Gotham City.
Taking the costumed persona of Poison Ivy, she begins a criminal career and sets out to show her power over men. Her first scheme involved threatening to release her suffocating spores into the air unless the city meets her demands. The Batman, who appears in Gotham that very same year, thwarts her scheme, and she is incarcerated in Arkham Asylum for the Criminally Insane. From this point on, she has a kind of obsession with Batman, he being the only person she could not control. Over the years, she develops plant-like superpowers, the most noticeable being a lethal toxin in her lips; she is able to literally kill with a kiss. Poison Ivy escaped from Arkham Asylum again and again, more often seducing her guards in order to make her getaway. She soon became a frequent member of Batman's Rogues Gallery, often committing robberies to fund her cause for preservation of all plant life. Poison Ivy soon came into conflict with many other heroes in her insane quest, such as Superman and Wonder Woman. She fought the Justice League at least once and joined the Injustice Gang to help oppose them.
Poison Ivy also offered her talents as a one of the world's leading experts on plant properties to the Secret Society of Super-Villains, although in recent years she appears to have left the team.
She hated all of humanity in many ways for the damage they had done to the world's flora. She allowed herself to temporarily sideline her mission to join the Suicide Squad. Under the direction of Amanda Waller, she served on several missions.
