Name: Anne Summerville, SC (Zone 8a) Only dead fish go with the flow!
Well that was quick I just checked my email Sue, you win first prize!!!
I am fairly sure that it's a kind of Slime Mould, a group of organisms once
considered to be fungi but now known to be quite different. I can't ID the
species, but you can see a small selection of Slime Moulds on my page here: