The Combustion Berry is a treasure in Pikmin 2 that is actually a large strawberry. It is found in 2nd sublevel of the Snagret Hole in one of the alcoves. It is the 3rd treasure on the List of Pikmin 2 treasures.
Captain Olimar's Journal
"I've collected all kinds of edible objects, but the ship's sensors can't judge taste. To make up for the ship's shortcomings, I'm making a special effort to try everything."
"Everything is best in moderation. This fruit is the perfect example of too much of a good thing. Its devastating sweetness is like an act of violence on the palate, scouring all with succulence..." .