darning egg or mushroom, Stopfei oder Stopfpilz

__A simple darning egg or mushroom, printable without support.__

At home we had a darning mushroom made of wood and I remembered this useful tool, so I designed one to print on FDM machines (i.e. Ultimaker, RepRap,...). It is designed for function and easy printability and not primarily for good design. I tested it and it works pretty well. And I think the design is at least ok while the _Darning egg or mushroom_ is in the sock (see below for details). ;-)

_What is a darning egg or mushroo