The Grinning Man used to be a really low powered criminal. While languishing inside a jail cell, he was approached by a lord of hell, Neron, who offered him powers in exchange for his soul. The Grinning Man agreed to it and asked for super strength, flight and the ability to disguise himself into anyone because he wanted something to “put a smile on his face”. Typical of a demon, the agreement came with a catch: the Grinning Man lost everything on his face except a permanent smile.
From – Nightwing Vol. 4 #102
