Canada 5 Dollars
In the year 1954, the Bank of Canada issued a new bill with the engraving of Queen Elisabeth II on it. But it caused the controversy as people saw the face of a devil in the Queen's hair, right behind her ear.
Though it wasn't very convincing, but because of peoples complains the bank destroyed all bills and reprinted them with a slightly changed version i.e. modify the face plates by darkening the highlights in the hair.
Devil's Face in Canada 5 Dollars | highlighted areas of the Queen's hair gave the illusion of a grinning demon behind the ear