Originally, Mr. Freeze was just another villain with a freeze ray. Called Mr. Zero in his first appearance, he was renamed for the 1966 "Batman" TV show, and the name followed him back to comics. Over the course of "Batman," he was played by three different actors, all of them legends in their own right: George Sanders, Otto Preminger, and Eli Wallach. In comics and on television, he was depicted as an intelligent criminal who had invented a gun that freezes things in ice, but thanks to an accidental explosion involving the gun, Freeze could only survive in a subzero environment, requiring him to wear a special suit. For decades, that's all there was to Mr. Freeze—a guy in a metal suit with a cold gun. The only thing that distinguished him from Captain Cold was that the latter could survive at room temperature.
Then the 1990s came along, and "Batman: The Animated Series" made Mr. Freeze into a tragic and even sympathetic figure. Victor Fries was a scientist who was deeply in love with his wife, Nora. When she contracted a terminal illness, he dedicated himself to cryogenic research that he hoped could prolong her life. When his boss interfered with the experiment, it led to the accident that turned Fries into Freeze. He continued to long for and carry on one-sided conversations with Nora, even though she was seemingly dead. She later turned out to be alive and frozen in suspended animation, but Freeze still had no way to revive or heal her. Over time, Freeze's condition caused both his body and his humanity to deteriorate, until on "Batman Beyond" he's just a disembodied head on robotic spider legs.
The same tragic origin was used for Mr. Freeze in Joel Schumacher's "Batman & Robin." As played by Arnold Schwarzenegger, however, Freeze was a comic character who made constant ice puns, lacking the pathos of his animated counterpart.
