Two-Face

Two-Face, formerly known as Harvey Dent, is a DC supervillain. Half of his face is scarred and he makes his decisions based on a coin.

Origin
Harvery Dent was once the district-attorney and a close friend of Bruce Wayne until mob boss Sal Maroni threw acid in his face during a prosecution. The attack scarred half of his face, as well as one side of his coin. After finding out how he looked like, he became insane and turned to crime, making his decisions based on his coin.