I found this cluster of mushrooms growing in my yard today. It had just sprung up, as they do, in a section of what we call "badger damage" - one of the many holes dug by the motherlovin' raccoons as they search for grubs around the roots of plants in late summer. (I'm glad I'm not a raccoon.) I put some sort of kill-o-zap powder on the lawn to stop the grubs developing and prevent the kind of damage we had last year, but it didn't occur to me to put it around the shrubbery and the raccoons are handily digging up all the bare areas. All in all, it's probably doing the garden some good.
The earth in that area was topped-up a few months ago with commercial compost, but none of it has grown a mushroom anywhere else in the yard. I assume the mechanical damage of the little vermin's claws is similar to 'casing' commercial mushrooms, where you break up the mycelium and give it a bit of fresh substrate to induce pin (baby mushroom) formation.
I don't know what it is, so I'm not going to eat it. At least one moth larva appears to be tackling it with gusto but that doesn't mean it's non-poisonous.
I once grew oyster mushrooms and blogged about it a couple of years ago. I didn't eat them either. Nasty things, fungi.