Calvatia gigantea, the giant puffball, appears in the fall in open meadows and forest edges, often returning to the same spot from the same underground mycelium. It can reach the size of a basketball, from my experience, and I’ve read about larger. It’s edible only when the inside is pure white and firm. Slice before cooking. Any yellowing or hint of gills means it’s maturing and no longer safe. I like to peel the outside layer off and chop up the center to use as taco filling, heavily seasoned.