It's been too dry in Massachusetts to see any fungi or slime molds--except in our compost container! This is Fuligo septica*, the "scrambled egg" or "dog vomit" slime mold. It's a weird organism, composed of millions of individual crawling cells acting together as a collective creature, eating bacteria and other organic matter as it travels. Eventually it finishes its journey and the mass changes from a foamy blob into a mass of spores that can continue the trip elsewhere. Fuligo septica has been a favorite on this blog for many years.
The black thing at the leading edge of the slime mold is a piece of plastic broken off the compost container.
* literally "Rotten soot"