For this mushroom, you only need a small amount of thin cotton yarn, in both white and red. Also, you will need 3 white beads, but you can replace them with crocheted dots if you want to.
I’ll post some in-progress pictures soon, to make the pattern easier to understand.
In the English version, I used US terms.

I hope you enjoy!

Pattern edit: On 8th Oct 2012, I added some more information to the pattern about working in joined rounds or spiral rounds.

Pattern edit: 15th jan 2013 New version added. If you want to add a loop op top of the toadstool, so you can make a charm out of it or whatever, it’s easier to crochet this in two parts. You stop crocheting after the first round worked in red, and then crochet the top of the toadstool top-down. It makes the top look nicer, too.