Batman’s archenemy is Alan Moore, his parents never really loved him and he was a drop out.
The Joker has no real name because his name changes as often as the person who embodies him, so it would be impossible to list them all. Nor does he have any defined origin story; some people say his madness came after falling in love with a woman whose smile resembled that of the Cheshire cat from Alice in Wonderland and stabbing her through-the-heart when she wouldn’t kill Bruce Wayne for him while other people say he got mad after being kidnapped by an obsessive fan of Batman’s named Joe Chill who shot him and stuck a fish hook in his mouth to make it look like he lost one side of his face