from left
Hush:
Thomas "Tommy" Elliot was a childhood friend of Bruce Wayne's. He targets both Batman and Bruce Wayne. Hush uses manipulation and guile instead of noisy "signatures". He is often described as a manipulative and deceitful "anti-Batman".
Riddler:
Edward Nigma aka Eddie Nashton is a criminal mastermind who has a strange compulsion to challenge Batman by leaving clues to his crimes in the form of riddles and puzzles. Recently, he has seemingly abandoned his criminal lifestyle and has opted to utilize his skills to turn a profit as a freelance investigator.
Harley Quin:
Dr. Harleen Quinnzel, a former criminal psychiatrist, fell in love with the Joker and became his most famous accomplice. She wears the outfit of a traditional harlequin jester. She affectionately refers to the Joker as "Puddin'" and "Mistah' J", and is best friends with Poison Ivy.
Poison Ivy:
Pamela Lillian Isley, a former student of advanced botanical biochemistry, employs plants of all varieties and their derivatives in her crimes. She has the ability to control/manipulate all plant life and is immune to all poisons and toxins. She is often described as fanatical about defending plants from other humans, even being willing to murder for her beliefs. She also has a severe love/hate relationship with Batman. In some instances she claims to love him, in other encounters she functions as an ally, and at other times she is more than willing to kill him.
Clayface:
Basil Karlo, the original Clayface, was an actor who was driven mad when he heard of a remake of the classic horror film he had starred in, The Terror. Adopting the persona of the film's villain "Clayface", he became a serial killer targeting the cast and crew. He was eventually stopped by Batman and Robin. Later, Karlo would be imbued with the powers of Clayfaces Preston Payne and Sondra Fuller. Additionally, his body sports crystals similar to quartz that endow him with greater powers. In this form he is known as the "Ultimate Clayface." He is the Clayface who is currently active in crime.
Killer Croc:
Waylon Jones is a former crocodile wrestler turned into a criminal deformed by mutation into a humongous humanoid lizard. He has low intelligence but great strength, as well as crocodilian abilities, such as a keener sense of smell and the ability to hold his breath underwater for long periods of time.
Ra's al Ghul:
Ra's al Ghul ("Demon's Head" in Arabic), is a centuries-old eco-terrorist. He knows Batman's secret identity. He utilizes special pits known as Lazarus Pits which enable him to evade death, and live for centuries. He is the founder of the worldwide League of Assassins, though exactly when is unknown.
Scarecrow:
Professor Jonathan Crane, an insane scientist and psychiatrist, specializes in the nature of fear. Dressed symbolically as a scarecrow, he employs special weapons, equipment and techniques designed to use fear to his advantage in his crimes.
Lady Shiva:
Sandra Woosan is first introduced as an antagonist to martial artist Richard Dragon, believing him to be a spy responsible for the murder of her sister Carolyn. In actuality, Carolyn's murder was orchestrated by Guano Cravat, a corrupt businessman whose criminal ambitions had been foiled by Dragon. Cravat convinced Woosan that Dragon was Carolyn's murderer, deliberately pitting her against Dragon in an act of revenge.In order to avenge her sister, Woosan drove herself to become a master combatant. During the course of her training, she discovered that she was a prodigy, rapidly mastering several martial arts and eventually dubbing herself with the ridiculous title of "Lady" Shiva.
Joker:
The Joker is an unrepentant homicidal maniac with a clown-like appearance who takes comedic delight in violent crime and challenging Batman. He is generally acknowledged to be Batman's arch-nemesis and worst enemy, gleefully citing the relationship between the two as being Comedy and Tragedy, Chaos and Order, two sides of the same card. He sometimes refers to Batman as "Bats" much to Batman's consternation. The Joker was responsible for the brutal murder of the second Robin Jason Todd
