Imprisoned from birth to serve his dead father's sentence, Bane was raised inside the horrific environs of a Santa Prisca prison. Finding solace in a smuggled book and meditation, he developed incredible powers of concentration.
When he was subjected to military experiments with the experimental steroid Venom, his iron-forged will helped him survive when other test subjects had died, and he manage to escape. Determined to prove his worth, he sought out Batman and broke the Dark Knight's spine. But Batman recovered and managed to best Bane, cutting off the precious Venom supply that transforms Bane into a superhuman.
An Arkham Asylum psychiatrist assigned to treat The Joker, Dr. Harleen Quinzel instead became obsessively fixated on her patient, believing herself to be in love with him. She helped him escape confinement and took on her own criminal identity as Harley Quinn.
Quinn is a violent and unpredictable felon whose only motivation, beyond general mayhem, is achieving The Joker's approval. Because of his cruel and mercurial nature, this in some ways makes her just another of his victimsâalbeit it a very dangerous one.
He briefly worked as a carnival freak under the name Killer Croc, but his misanthropy grew as did his bestial nature, pushing him to a life of crime. As his physical condition and mental state deteriorate, Killer Croc becomes a more bestial foe, increasingly detached from humanity.
Botanist Pamela Isley was transformed by a science experiment gone wrong into a plant-human hybrid. With chlorophyll flowing through her veins instead of blood, she developed a toxic touch and a pheromone-fueled talent for seduction.
Her crimes have become more ecologically focused as she has increasingly abandoned her human side, identifying more with the natural world. Her unique brand of eco-terrorism often puts her into conflict with Batman, whose iron will usually protects him from her seductive powers.
The self-styled Clown Prince of Crime has no superpowers, beyond a capacity for incredible violence and a skill at creating deadly mayhem. He frequently concocts elaborate schemes to entrap his arch nemesis, Batman.