67. Mr. Freeze

Victor Fries had an obsession with freezing things even as a small child, which led him into the field of cryogenics. When his wife Nora fell seriously ill, he discovered a way to cryogenically freeze her body until a cure could be found.

Fries' colleague attempted to stop the process, and the ensuing struggle doused Fries with hazardous chemicals. These chemicals induced strange physical changes in his body: his skin grew pale, he could only survive in sub-zero temperatures and his mind became fractured. Fries created a containment suit that served to protect his body and augment his strength, as well as a gun capable of flash-freezing anything in its sights.

With his wife gone and his grip on humanity shattered, the newly dubbed Mr. Freeze began terrorizing the citizens of Gotham City. His gun became a way of inflicting on others the pain he feels in his own heart. Though his crimes typically serve little purpose, Mr. Freeze is still coldly ruthless and one of Batman's most deadly foes.

Pathos is a key ingredient in any great villain, and Freeze has tons of it. This man dedicated his life's work to curing his cryogenically-frozen wife's cancer, and just happened to fall victim to one of those unfortunate accidents that seems to always befall comic book characters. Who can't relate to that?

More importantly, Victor Fries' loss is as deep as Bruce Wayne's, which makes him such a dynamic antagonist. To up the stakes even further, the comics have progressed Mr. Freeze into a truly deranged lunatic, one who has given up all hope of reviving his dead wife and accepted a career of unadulterated murder. Good stuff.