Christmas tree decorations have changed considerably over the years.  Which of the following well-known products became popular after being promoted as a Christmas tree "decoration"?

Cookies cut into animal shapes had been sold in America since at least the late 1800s, but in 1902 Animal Crackers took off as a commercial product.  Nabisco (then the National Biscuit Company) packaged their cookies in a box shaped like a circus wagon, capitalizing on the popularity of Barnum and Bailey's circus.  Then they added a string to the box so that it could be hung on Christmas trees.  This somewhat strange-sounding idea was received so well that "Barnum's Animal Crackers" soon became a year-round success.