Leftie is a fan character who can be found on Tumblr.
Leftie has long horns with pierced holes in the center, four points on his lip, and a long scar diagonally across his torso. In his left horn is a tag which is set to give him an electric shock if he gets out of line. He's chubby, most likely from constantly eating, but he's not out of shape.
Leftie is the sort of guy to make death threats for no valid reason. He'll threaten enemies and friends alike, though he wouldn't actually hurt his friends. He loves food and sometimes will eat items that aren't considered food (chips bags, cysts, cardboard, etc.). He also likes to draw, play video games, and steal from the human world.
Leftie was the sort of demon who would kill reincarny catchers, which greatly upset Luke. When Luke tried to confront him about it, however, Leftie attacked him. Leftie was placed in purgatory as punishment. He has spent the past eight years in there for his rehabilitation.