Burger King fries with an onion ring on them, and some people believe that the chain puts the ring on purpose as a way to make their fries more appetizing. There is no definitive answer to this question, as no one knows for sure whether or not Burger King puts the onion ring on their fries on purpose.
However, it seems as though the chain might be doing this in order to draw in more customers. If people are more likely to eat fries with an onion ring on them, then Burger King will likely make more money.