Doctor Who: 20 Things You Didn't Know About The Tenth Doctor
8. He Adopted A Cat To Help Him Get Over Rose
A Rose by Any Other Name was a comic-book story in which Ten, distraught at the loss of his beloved Rose Tyler, adopts a cat named Rose to help him get over her.
Yep, nothing mildly psychotic about that behaviour.
Rose the cat gets up to all sorts of weird stuff, including ripping up the Doctor's clothes, getting into fights with K9, and even piloting the TARDIS.
A cat got to fly the TARDIS, but Jackie Tyler wasn't allowed. Typical.
In the end, Rose the cat left her Time Lord companion after he decided it was time to take on another human friend. Still, she left her claws on the show's history - the comic's 22 issues technically make it the longest-running serial in Doctor Who history.