The Giggler

This here is Myron Stotler, AKA The Giggler! An undisclosed freak accident left him with a unique ability: his infectious laugh. Anyone who catches so much as a chuckle from his nefarious mouth will find themselves incapacitated with uncontrollable fits of laughter. He uses this hideous talent to rob banks.

Which he is clearly on his way to do, as those sacks are obviously empty.