Batman -- Bruce Wayneruns Wayne Enterprises in Gotham City. Bruce’s parents, Thomas and Martha, were killed in a mugging gone awry when he was a child. He’s spent most of his life with the family butler, Alfred Pennyworth. Alfred is one of the few people that know of Bruce Wayne’s alter-ego. To deal with the trauma suffered in his formative years, Bruce develops into Batman in an attempt to help rid Gotham City of the types of criminals/crimes that ultimately took his parents from him.
Robin -- Dick Grayson and his parents, Mary and John, comprise a trapeze troupe that travels with the circus. While in Gotham City, Dick’s parents are killed when a mobster sabotaged their equipment. Bruce Wayne was in the audience and saw what transpired. Given that he suffered a similar trauma, he takes Dick under his wing and trains him to fight alongside him. Dick assumes the alter-ego of Robin.
Rogues Gallery:
The Joker, alias Jack Napier, was a mob associate. He and some fellow gangsters broke into the ACE Chemical Plant. Once there, they encountered Batman for the first time. During the ensuing scuffle, Napier fell into a vat of chemicals and was swept out to the river via a drainage pipe. The chemicals ended up turning his hair green, his lips red, and his body a bright, white color. It also left him with a permanent smile on his face. Given his ghastly new appearance, he christened himself the Joker and became Batman’s greatest nemesis in Gotham City.
The Penguin is a criminal mastermind that aspires to be wealthy, powerful, and respected. He wears a monocle, top hat, and tuxedo. He carries his signature, weaponized umbrella with him everywhere he goes. Penguin is depicted as being short, rotund, and waddling like a penguin.
Catwoman, formerly known as Selina Kyle, is a cat burglar that uses a bullwhip as a weapon. Selina Kyle is often depicted as being a love interest of Bruce Wayne (Batman).