It’s been fairly wet for Denver recently. When that happens, I tend to see large mushrooms show up in my lawn (the largest ones here are about 6″ or so across):
This evening, I needed to mow the lawn before it rained again. I found this beneath one of my rosebushes:
I figured it was some sort of fungus, so I did a websearch for photos I could match it with. I found an Australian page (Adelaide area, which is interesting to me because I have relatives there) that identified it as a slime mould (his spelling).
Given that, I found another page that identifies it as an early stage of Fuligo Septica, commonly known as scrambled egg slime or dog vomit slime mold, and there are some disgusting photos of the later stages. It is, apparently, the only slime mold that can concentrate heavy metals without damage to itself.
What I found slightly unnerving is the statement that “This creeping fungus moves very slowly in amoeboid fashion.”