What is this, and why is it so special?
This is a slime mold. It is called Fuligo septica. It is also known as the Dog Vomit Slime Mold, as icky as that name may sound. Slime molds are very strange life forms. They are not molds, and are not even in Kingdom Fungi. They are not animals or plants either. It is currently considered a Protist, but that may change as we learn more about them. The yellow blob moves, flowing along slowly to eat bacteria and other organic matter. This one is mature, and is forming its next stage, where it will become very dry and brittle. At that point, if something bumps it, it will break, releasing a cloud of tiny spores, which will float through the air, and eventually grow into more slime molds.