I have had these ugly toadstools growing in a corner of my garden for the past 5 or so years. I tried to find something on the internet that looked like these but the only thing somewhat similar was something called Dead Man's Foot. When I first saw them I though a large dog had left me a present because they really look like a turd. They always come up in the same spot several times a year and I try not to disturb them because if they are bumped or kicked a fine brown cloud spreads through the air. I don't know if breathing the spores would make you sick. I will continue to watch this one and photograph it as it changes. A couple of weeks ago I had my gartdener cover the area with mulch and they are coming up through the mulch.

Here is a link that might be useful: