The TARDIS is a phone-box-shaped interdimensional vehicle.
Description
The TARDIS is a bigger-on-the-inside time machine which usually takes the form of a phone box, also capable of traveling between universes. Though it has a will of its own, the machine is owned and steered (somewhat haphazardly) by the Doctor, an ageless Time Lord from another universe where Mickey Mouse exists only as fiction.
The Doctor has used the TARDIS to travel to the Prime Universe on several occasions, befriending Mickey Mouse, and thus became a staunch advocate of the Disney fictions of his home dimension's Earth.
At some point, Scrooge McDuck got his hands on the TARDIS and, after loading his fortune into its infinite stash, used it to travel back in time to 1896 and meet his younger self just fresh of finding the Goose Egg Nugget, though quite what he meant to do is unknown. Having no further use of the machine, Scrooge later put it up for sale as the sole wares of a 'Slightly Used Tardis Lot', and it was presumably recovered (for a price) by the Doctor.
Behind the scenes
The Doctor's TARDIS, central to the non-Disney long-running science-fantasy TV series Doctor Who (where it debuted in the 1963 episode An Unearthly Child), has made a few appearances in crossovers between the Doctor Who universe and the Prime Universe; first in the 1975 TV special Disney Time 1975, and then, under the pen of Don Rosa in 2015 in two illustrations, Tardis for Sale and Ducktor Who (which appear to take place in the reverse order to their release). It is also a major element of the crossover video game LEGO Dimensions.