Howdah
From Tardis Wiki, the free Doctor Who reference
A howdah was a carrier placed on the backs of elephants in India. (TV: "The Watcher") Howdahs were strapped onto the creatures and were canopied, but with open sides. Their box-shaped design usually allowed for two people to ride on top, sat side-by-side. Howdahs were often elaborately decorated, typically with tassels. (PROSE: Ghosts of India)
The First Doctor mentioned to Steven Taylor that if the TARDIS's chameleon circuit was functioning correctly, the TARDIS would possibly take the form of a howdah if they landed during the Indian Mutiny. (TV: "The Watcher")
The Tenth Doctor and Donna Noble used a howdah when they travelled by elephant with Gandhi. (PROSE: Ghosts of India)
