The pleated caps are a hint that these are some species of inkcaps. The general shape and size suggests glistening inkcaps, but they are usually a more subdued brown.
The original mushrooms looked like they may have been up for some time, and got into a state were they were already hard to identify confidently. The patina of mould didn’t help.
Growing in the gap between a garden wall and the pavement, this a a cut-leaved dead nettle. It’s not actually a nettle, and “dead” in that it doesn’t sting.