Strange Mushrooms In the Garden

Some very strange mushrooms have appeared in one section of my vegetable garden, close to where the squash and cucucumber plants have been growing. We've looked them up, but it seems highly possible that they are toxic, so we're not eating them. Too bad, because they look like they would be delicious. This is the second crop! I pulled a bunch out last Saturday, and by Tuesday they had returned. We are puzzled, and wish we could consult with our old friend Richard Koppel, a self-taught mushroom expert.