Hatbox

A Hat box was an object for carrying hats.

The Doctor jokingly 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 Tenth Doctor again. She did and handed it to him to carry. (DW: Partners in Crime)