Looks like a destroying angel (e.g. Amanita virosa) to me. This and the death cap together account for the vast majority of mushroom poisonings in the world. Cooking it will not destroy the toxins, nor will acid. Symptoms tend to appear 5-24 hours after eating, too late to pump the stomach. Half a mushroom can be enough to kill you.
I don't recommend going out to pick mushrooms unless you know what you're doing. If you do, stay away from the white ones. You can still get terrible stomach cramps and diarrhea from other colors of mushrooms, but the white ones have the most dangerous species.
I remember being on a wilderness weekend many years ago and being told that when you cut the stem on some poisonous shrooms they discolour a sort of blue tint. I'm lucky, I hate the taste and texture of mushrooms.