I'd like some help identifying what the heck these things are. Are they mushrooms that have just started to grow? And should I be worried about them? They are only in one section of one garden box. I used the same soil in both boxes and turned it so I'm assuming that it arrived after I planted? It is only located in the same area as the pole bean plants, not sure if that is significant or not. We also experienced a very rainy weather pattern over the last two or three weeks although I think these were there before all that rain.

They are about 1cm tall. The outside "layer" looks papery and inside there are 3-5 purplish black little... things. I have seen these strange things before.