The Stink Hat

Description
This floppy and stained hat is (probably?) made of dark felt. It looks about a hundred years old, and even the most generous observer would suspect that it has served at least a few seasons as a squirrel nest. No matter how well cared for or how thoroughly washed, the hat looks stained and trampled, and smells of freshly upturned soil and pine sap. It is definitely odorous, just not particularly malodorous.

Owner/Wearer
The Stink Hat is proudly owned and worn by David, a traveler from another world. It was supposedly found in the Tower of Kela. There is no previously known owner of the hat. Dave doesn't mind how the hat looks or smells at all - the Stink Hat is by far the most comfortable hat he's ever worn, and it give him a well-traveled look that he appreciates.

Powers
Despite it's aggressively humble appearance and scent, the Stink Hat boasts incredible powers!

Hat of Holding
The Stink Hat's primary function is as an extradimensional container, similar to a bag of holding. All manner of items can be stored in the hat, and yet it always weighs less than a kilogram.

Durability
The hat is incredibly tough, repelling spear blows as if it were made of boiled leather. It regenerates any damage done to it within a day. It also acts as armor against any attacks directed at the wearer's head.

Mage's Friend
The Stink Hat grants the wearer improved resistance to spellcasting drain.

Portable Home
The greatest power of the Stink Hat comes when it's removed. Once each day, the owner can command the hat to transform into a secure cottage that greatly resembles the hat. The transformation to cottage size takes ten minutes, but just three seconds to shrink down once all occupants have left.

Inside the house, all of the items previous stored in the hat are neatly organized in various cupboards, closets, shelves and racks.

There cottage features a common room, a study/master bedroom, a kitchen, a bunk room and a mysteriously advanced bathroom with running water.