FoodSweet
Chocolate Frog
A Chocolate Frog is a sweet that hops until it is caught. Each one comes with a collectible card of a famous witch or wizard. Harry’s first card is Albus Dumbledore, and the caption mentions Nicolas Flamel, which is how Hermione later identifies the Philosopher’s Stone.

First mention
Harry Potter and the Philosopher's StoneChapter: The Journey from Platform Nine and Three-Quarters
Harry buys Chocolate Frogs from the trolley witch and opens the Dumbledore card with Ron.