Nancy Morin thought at first it was a metal ornament but it turned out to be a group of Big Laughing Mushrooms, also called Giant Gymnoplius.
Christina Gonzales found some too, and her photo shows the stem and underside of the caps.
Their name "laughing" refers to hallucinogenic qualities that are sometimes found in this mushroom. That is so in other parts of the world but here in Northern California that quality is inactive. They are not edible and they are often found here growing on pine stumps.
Thanks to Nancy and Christina for allowing me to share their photos with you here.