The following is a response to the story posted by FormerVengeance here, as well as the various follow-ups. Also, be warned that it may change with future installations.
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"You've been on a cube kick recently, Carol."
Carol grunted, but didn't turn around. Sine wasn't wrong, though - most of the things running around the TARDIS looked like they had been cut from cubes, or had been cube-shaped some time ago. A reddish, eagle-shaped creature whistled as it flew in circles around the central column, follwed closely by a white-and-black, angular tiger, whilst a yellow, squared-off lion and a boxy green elephant pushed against each other, trumpeting and snarling irritably. Some might have suspected the technopath had been foiled by a Rubik's Cube at some point, and this was her way of taking vengeance upon the obtuse nature of the puzzle.
The problem was, she'd been like this ever since the adventure to save Ceneric. And it was all too obvious why Carol was doing this.