O.K. Don't have a picture, but it's gross. I did read another similar post, but think mine's different. Starts like a small, hard round button, gets larger and lumpier. If I pull it out, it has a yellow sulpher-like powder on the root side (no roots). It is very heavy and dense. If left to grow, it eventually looks like it's melting and dying, shriveling up. It looks like some kind of horse poop. UGLY.
I don't know much about gardening, thus joining this group for support.
So, like I said in the other thread, lumpy yucky looking fungus is usually slime mold. There's even one commonly referred to as "dog vomit slime mold" ....