Dr. Victor Fries, through tragic circumstances, became known as the villain Mr. Freeze.
Fries was one of Gothcorp's most brilliant scientists and cryogenic researchers. When his wife, Nora became infected with a deadly disease, he developed a special freezing cell and planned to cryogenically hold her until a cure was found. The experiment, however, was interrupted by Ferris Boyle, C.E.O. of Gothcorp; A fight ensued, and the resulting explosion smashed Fries into his cryogenic freezing tanks. The accident soaked Dr. Fries's entire body with the freezing solution and rendered him unable to survive outside of a sub-zero environment. He vowed revenge on those who had wronged him and created a vacuum tight suit which maintained his body temperature at 50 degrees below zero and tripled his strength. After building a laser-powered cold gun, "Mister Freeze" was born.
Driven by hatred over the destruction of his life and maddened by his condition, Mr. Freeze sought revenge on those that had victimized him. He first attacked Boyle and Gothcorp, and though his plan was stopped by Batman, the Dark Knight presented evidence that led to Boyle's arrest for his misdeeds. Freeze, however, was arrested, and placed into a sub-zero holding cell to live the rest of his days.
Mr. Freeze becomes bent on destroying Batman since he blocked his mission for revenge. He is a quiet, but dangerous adversary. Mr.Freeze is an angry and saddened man, who is sentenced to Arkham Asylum when apprehended. A special cell is designed to maintain his need for a frozen environment. He is alone and his only motivation comes from his wife's music box, which he holds as his last piece of the happiness he once had. He is viewed as an loner by the rogues gallery, and generally does not hold alliances with any of the other inmates of Arkham. Batman knows he is a dangerous adversary, and that the traumas that have occurred in Mr.Freeze's life are scars which will never heal.
Grant Walker discovered Nora's frozen (but living) body. An entrepreneur and businessman, he used her as a bargaining chip to gain what Freeze had always seen as a curse: immortality. Freeze transformed Walker's cell structure to a frozen prison similar to Freeze's. Upon completion, Freeze betrayed walker and destroyed the "utopian" society he'd been building. Freeze then secluded himself in a self-made ice block, floating to colder waters until he finally settled in the Arctic. He stayed there with Nora, continuing to look for a cure..
Unfortunately for Freeze and Nora, an exploration crew inadvertently crashed into Freeze's home. The containment was destroyed and the deadly disease to progressed into its fatal stages. After freezing the entire crew of the sub, Freeze headed to Gotham City with Nora, his surrogate son Koonak and his two polar bears Notchka and Shaka, to enlist the aid of Gregory Belson. Belson, a head cryogenic researcher, had worked with Freeze prior to the accident. Though he was hesitant, Belson was eventually "persuaded" to aid Freeze.
Together they found a way to cure Nora's disease, but it required an organ transplant. With no deceased donors available, they were forced to pursue a live one. The "donor" they chose was Barbara Gordon, and proceeded to kidnap her. However, Dick Grayson was present during the kidnapping, and though he failed to save Barbara, he was aware of Freeze's plot. Batman and Robin managed to interrupt the operation before it took take place; the battle that ensued caused Freeze's lair to explode. Batman, Robin, and Barbara were able to evacuate Nora and Koonak in time, but Freeze had fallen into the fiery blast and was assumed dead. In actuality, he and his polar bears survived and, for a time, wandered the Arctic.
In Gotham, Nora was cured. She waited ever patiently for Victor to return, but he never made effort to contact her. In reality, the accident that had caused his "immortality" had actually deteriorated his body. Though his head was able to continue functioning, the rest of him withered away. He constructed an insect-like robotic carriage for his head, as well as a larger shell resembling his human form.
Resigned that he would never again be united with his beloved Nora, a new layer of ice froze over Freeze's heart. Having lost that which was most precious to him, he resolved to stamp out warmth wherever it glows. A newer, more powerful, and chillingly sardonic Mr. Freeze lost his obsession over his wife and instead concentrated on bringing misery to the people of Gotham and its protector, Batman. However, Batman and Batgirl stopped the plan, and Freeze disappeared.
The head of Fries laid dormant for forty years before his destiny was intertwined with a new businessman: Derek Powers. Looking for a way to cure Powers' condition, Dr. Stephanie Lake proposed a cunning solution: transfer his consciousness to a new body. In order to test it, however, she needed an adequate subject. As Fries's condition was irreversible, the idea of a normal life was more than enough for Fries to cooperate. The process seemed to work, and Fries was temporarily restored to good heath. Eventually, though, his condition took a turn for the worse; as a result, Dr. Lake opted to terminate the experiment. Betrayed yet again, Mr. Freeze returned to exact revenge on those whom he felt wronged him, and after a confrontation with Blight and Batman (Terry McGinnis) Fries was assumed dead.
Much like the other characters of Batman: The Animated Series, Mr. Freeze underwent a stylistic change when the show transferred to The New Batman Adventures. His changes were subtle, and the character's story was augmented with the introduction of his deteriorated body.
Mr. Freeze had been a rather poorly received, clownish "villain" from the old live action Batman television series and the DC Comics of the 1960s prior to Batman: TAS. Paul Dini and Bruce Timm re-imagined the entire history and motivation of Mr. Freeze to produce a deadly serious threat rather than a buffoon. The creative team invented the character of the terminally ill Nora Fries to flesh out the backstory of a fully-realized tragic villain. It was the first complete overhaul of a pre-existing character in the DCAU, and to this day it is arguably the most successful.