This strange growth appeared on the end of a log in my small log-pile. A little larger than half a golf ball, it looks like a shiny silver brain, albeit a bit tarnished around the edges.

I assumed it was an unusual fungus but a bit of research has me thinking it's actually a slime mould, "the false puffball" (Enteridium lycoperdon) in its reproductive phase. A few days later it was gone, leaving nary a trace, presumably having dispersed its spores.

Never having found a slime mould before, and them being somewhat bizarre organisms, I'm a bit stumped as to which category to file this post under!