Fuligo Septica, or Dog Vomit Slime Mold, as it is more widely known. Apparently you cannot get rid of it. The good thing is that it isn't harmful to plants or people. It's actually a delicacy in Mexico, like its cousin, Huitlacoche (corn smut).
Confused and afraid of what it could be (I first thought it was vomit, seriously, until I noticed it had friends...), my first reaction -- which was very human, and even more American -- was to kill it. I took a stick to it.
This very slime mold was the inspiration for the 1958 classic, The Blob. It just keeps going, and going, and going...
In hindsight, I feel kinda dumb. Not to mention that I didn't really kill it, just disturbed it. Well, I guess I'll have to befriend it, but I doubt I'll be sharing any Scotch with it.