We found this giant mushroom by the pond in our yard. I had never seen one before and we were very surprised at the size of this mushroom. It looked like a giant ball and had a leathery textured surface. We looked it up and found the following. Calvatia gigantea, commonly known as the Giant puffball, is a puffball mushroom commonly found in meadows, fields, and deciduous forests worldwide usually in late summer and autumn. They also said it was excellent for eating, but we resisted going that far. This one, when we first found it was about 12-15″ in diameter. After we had moved it, the Giant Puffball, over time, started losing its firmness and mass.