These are called mushrooms I believe, had been growing on my door for a few weeks. It's monsoon here. Last night I took a picture of it and it looked like this . Today when I woke up it became like this: . All this within 12 hours. I'm pretty sure nobody touched the fungus so I'm inclined to believe this was spontaneous.
There are several fungi that autodigest their lamellae to release spores. Yours seems to be one of them. Due to the black liquid they release during autodigestion, they have the common name inkcap.
As an example, read this Wikipedia article about Coprinus for more details.