Wonka Longlasting Gobstoppers 50g
According to Roald Dahl's book Charlie and the Chocolate Factory, the fictional Everlasting Gobstopper is a candy that not only changes colors and flavors, but can never be finished, and never even gets smaller. It is implied that they may also be indestructible. Factory owner Willy Wonka explained that they were "for children with very little pocket money".