Recommended consequences of myconid consumption?

I’m a DM of an OOTA campaign where the party is considering eating Stool, the myconid from the prison. Considering the whole "don’t eat mushrooms you find in the woods" thing we’ve all been told, I felt it would be a good idea to give some kind of consequence. Maybe he’s poisonous, or some kind of LSD. Could I get some recommendations for what kind of effects they could get from eating Stool? I know this seems like a VERY open, opinion based question, but I’m looking for something with some research behind it. Maybe there’s a book or resource on Myconid biology? I need something researched and accurate to what would actually happen. Additionally, if it would change if Stool was cooked instead of eaten raw, please include that too.