Chlorophyllum molybdites, which has the common names of false parasol or green-spored parasol is a widespread mushroom. Highly poisonous and producing severe gastrointestinal symptoms of vomiting and diarrhea, it is commonly confused with the shaggy parasol, and is the most commonly consumed poisonous mushroom in North America. Its large imposing appearance and similarity to the edible Parasol mushroom, as well as its habit of growing in areas near human habitation, are reasons cited for this. The nature of the poisoning is predominantly gastrointestinal.
it looks like the shaggy mane especially at first... grows in poo in lawns all over the US