Hatbox
From Tardis Wiki, the free Doctor Who reference
A Hat box was an object for carrying hats.
The Fourth Doctor jokingly told George Litefoot that Leela was found floating down the Amazon in a hat box. (TV: The Talons of Weng-Chiang)
Donna Noble had a hat box prepared on the off chance she would meet the Tenth Doctor again. She did and handed it to him to carry. (TV: Partners in Crime)