Hi. Found this in my clone this morning. Beneficial, non-beneficial?
Not positive but with the mushroom being there I’m willing to bet that you are keeping your soil too wet
Idk but don’t eat it 
Cool! I’ve found a few myself in some of the soil ingredients - usually cow manure - but they usually die when exposed to the light. I personally wouldnt worry unless you get a massive mushroom bloom where they pop up everywhere out of control. Good sign - shows plenty of potential nutes for your clone to grow with. Ever see mushrooms in dead soil??? lol!
Thanks all, appreciate the responses. Yes, so the little guy died the same day (exposure to sun). Going to lighten up on the water a little, and glad to know nutes are good.