Buster Clusters are the homemade chocolates that Buster and Arthur made in "Buster's Sweet Success" to make up for the chocolates Buster was supposed to sell, but ate instead. Many people bought it, including their school principal, Mr. Haney. All of the customers eventually found out that the chocolate tasted terrible, and they wanted their money back. In the end, they became prank chocolates in Jack's Joke Shop.