Mentos is a candy mint with a hard outside and a chewy center that comes in various flavors.

If you've ever been to YouTube, you are probably familiar with one of the dozens of videos of people creating geysers of soda by plopping a single Mentos candy into a two liter bottle of Diet Coke. The chemical reaction of the two products indeed creates an impressive blast of soda--but if you are going to recreate the experiment, take care to do it somewhere with easy clean up!