Redman was a victim manipulated by Flumpty Bumpty who drank lava and lived (kinda).

His background before turning into a skeleton is unknown. He often behaves like a hacker, which is clearly seen when he turns off the cameras and acts as a computer virus.
He appears to be a tall, long, slim and blood-red skeletal figure with an exposed ribcage, four long legs and three points at the bottom of his head that can sometimes open like a spider's mandibles. 
Redman uses his ribs to climb out things.