Cool note. Polluting everything for greater modern forward world!  

Since these notes were made in New York, you have to wonder if the American Bank Note company had someone on staff to proof the designs for typos or secret messages slipped into the bill by a mischievous staffer. I mean, for all I know the main character says KNOCK KNOCK, and the other one says WHO’S THERE.

Well, it is a pictogram of a human in a doorway, so it’s not that far-fetched.