Wildlife Spotting

I don't exclude it completely, but I really doubt it to be a Fly Agaric...this one was just about 3.5 cm in the cap's diameter, very short stemmed (which couldn't even been seen clearly). I think it's more likely a immature Sickener or Beechwood Sickener (not at least because it was found in beechwoods - look at the beechnut shells on the ground) - but thanks a lot for your suggestion anyway