An enormous fungus.
The one on the picture was at least up to 30cm. high !
Maybe its hugeness is not so clear noticeable in this shot because I had to take it from a non-optimum pov, as there was a deep brook between the fungus and me, but I can ensure you : it was a real giant.
Dutch name : Reuzendikhoed
German name : Riesen-Krempentrichterling
Latin name : Leucopaxillus giganteus