Pop Rocks

Pop Rocks is a carbonated candy with ingredients including sugar, lactose (milk sugar), and flavoring. It differs from typical hard candy in that it creates a fizzy reaction when it dissolves in one's mouth.

Empath: The Luckiest Smurf stories
In the EMPATH: The Luckiest Smurf story series, Greedy created these kind of candies as a novelty for the Smurflings to try out. In the mini-story "It's The Real Thing", Nabby used them in conjunction with Smurf Cola in order to give him enough gas so he could win the burping contest he and his fellow Smurfs were participating in. The Smurflings thought that mixture of Smurf Cola and Pop Rocks together could make one's insides explode, but despite merely giving himself a stomachache, Nabby proved that rumor to be false.