he's a real fungi
I really like drawing fungi (yes, I worry about myself sometimes). You can really take liberties when drawing toadstools and fungi. The thing about fungi is they come in so many weird shapes and colours, that no matter how much you exaggerate the image it still is plausible. In the world of fungi anything goes.
It doesn't just stop at its appearance either, the names are pretty mad too; Fairy Ring Champignon, Wood Hedgehog, Weeping Bolete, Death Cap, Destroying Angel, Satan's Bolete to name but a few. And, I'm betting the guys who named them were partial to a few of the Magic variety.
Ink is one of my favourite mediums and it just seems to work so perfectly with this subject - and I believe that some inks are actually fungi based. I am certainly no expert on fungi, I just like to make up my own. I have named this one Old Jack's Cap.