Mr. Freeze

Originally called Mr. Zero, he was renamed and popularized by the 1960s Batman television series, in which he was played by several actors. His character was used because the series creators had originally wanted to use the character of Two-Face (aka Harvey Dent), but network executives thought the character would be too scary for the numerous children who watched the show; as a result, an alternative villain with a physical deformity and a more serious personality, Mr. Freeze, was substituted. Initially, the producers sought Clint Eastwood to play the role, but instead later went with other guest stars.

Over two decades later, a television adaptation of Batman revitalized him once again. Batman: The Animated Series retold Mr. Freezes origin in a landmark episode by writer Paul Dini, introducing his terminally ill, cryogenically frozen wife, Nora, which greater explained his obsession with ice and need to build a criminal empire to raise research funds.

The episode was seen as groundbreaking for a Saturday morning cartoon and helped set the tone for the complex moral motivations seen constantly in the rest of the series. This backstory was also made canon in the comics and has been Fries' official origin in almost every incarnation of Batman since. This leads many fans to think of him as the most sympathetic villain and in some cases, merely as an antihero antagonist.

Elements of this back story were incorporated into the 1997 film Batman & Robin, in which he was portrayed by Arnold Schwarzenegger.