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