Laughing Jack -- Not just a murderous clown from Creepypasta

Alternatively known as Laughing Jim, Giant Flamecap, Spectacular Rustgill and Prächtiger Flämmling, all of which are acceptable names for adventurers in a Fritz Leiber novel, singly or together.

According to one guide, "A yellow cortina covers the gills of the immature fruitbodies, breaking and shriveling to leave fragments around the rim of the cap and around the stipe." I think they're just making that up. "Fragments of cortina around the Stipe" sounds suspiciously like a re-make of that Sledgehammer video.
This time of year they sprout in impressive clumps from tree stumps or logs, or in this case from a piece of log that must have been ploughed just under the soil during the last round of landscaping.

Some are said to contain psilocybin, but they are also hideously bitter, and may contain a range of other neurotoxins, and there are some things even I won't eat. Now using them to flavour beer, that's another matter.