We’ve got some giant puffball mushrooms growing here.
Here’s a photo of a cluster of them with a penny set on top for scale.
When I saw them, I wondered why there were a bunch of volleyballs scattered around. Calvatia gigantea turns out to be relatively common and, according to several sources, edible and tasty. Once you’ve verified that the interior is firm and white, it can be battered and pan fried, or used like tofu. It smells strongly like your standard grocery store issue mushrooms. Which, unfortunately, I detest, so no giant puffball will be appearing on the household menu anytime soon.