Vagician said:

I think it is some sort of Coprinus, aka inky cap. Hard to tell since the cap is just pushing through the soil but this is a good sign of healthy soil. Once it is older it will start to "melt" and drips a black, inky substance along the edges of the cap. That's normal and it is just how the spores spread. Honestly, I'd take the cap when it is melting and mix it in with your cannabis soil. The fungi feed the soil and that feeds your plant.

Click to expand...

tamyam420 said:

i would eat it :)
sorry i have no clue. Do you think it was from the medium or something you put into it. Either way means there's some life in there

Click to expand...