A Peppermint Toad was a magical peppermint cream shaped like a toad which "hop[ped] realistically in the stomach" when it was consumed.[1]
These sweets were sold at Honeydukes in Hogsmeade.[1][2] One day in 1993, the day after a weekend trip to the village and the first day of the holidays, Harry Potter found Ron Weasley rubbing his stomach as he ate a Peppermint Toad, presumably because it was jumping around inside him.[3] Later that same school year, during a party in Gryffindor Tower celebrating Gryffindor's victory over Ravenclaw at Quidditch, George Weasley threw Peppermint Toads bought at Honeydukes into the crowd of Gryffindors.[2]