Hugo Strange

Hugo Strange is the owner of Arkham Asylum and one of the most dangerous villains in Batman's rogues gallery, much so because out of all of Batman's villains, he was the first to deduce Batman's identity as Bruce Wayne. Hugo is also the deranged owner of Arkham Asylum. He claims to be sane, however he is just as crazy as the inmates he claims he is treating. While not seen or confirmed, it is implied that he employed Harleen Quinzel as a psychiatrist at Arkham. After she became Harley Quinn, Hugo employed Jonathan Crane as the new psychiatrist at Arkham. However, after he found out about Crane's fear toxin, fired him so that he could take credit for his work. This lead to him being attacked by Crane, now going by "Scarecrow". After the effects of the toxin he was sprayed with wore off, Hugo continued to conduct experiments on the inmates at Arkham.

Hugo uses the experiments he conducts to analyze the psychotic personalities of the inmates at the asylum he owns. While Hugo was able to figure out Batman's identity, he didn't manage to reveal it due to Batman threatening to lock him in a cell with The Joker. Hugo kept quiet about Batman's identity, and Batman keeps a close eye on the professor.