Bonbon is both: an item and a food in Pajama Sam 3: You Are What You Eat From Your Head To Your Feet. It is needed to get the key that unlocks the gate to the prison.
Only one bonbon can be obtained when Sam is thrown into prison. It is obtained by collecting one from a pile of bonbons. If the player tries to pick another bonbon, Sam will eat it rather than collect it. If the player throws it at the key, the player can use the key to escape prison.