Jeff The Killer

Jeff The Killer, real name Jeffrey Woods, is one of the main characters of Mary-Chan No Samurai. He is a teenaged Serial Killer with a Glasgow smile who carves a Glasgow smile into Mary-Chan's face and murdered her.

He also has unexplained demonic powers, apparently.

Trivia

 * No one knows where the image actually originated from, the earliest known use is on Japanese image boards in 2005