Coprine is a pretty crazy toxin. If you eat a Common Ink Cap by itself, you may not feel much of anything. But if you have even a little bit of alcohol, even up to three days after eating C.atramentaria , you will feel terrible.
another great post @dber! Really is kind of amazing some of the "odd" compounds and other toxins mushrooms "come up" with.
Coprine is one of the most specific ones to be sure. The variety of toxic substances is very impressive though by any metric.