The pony's mane looks like the Doctor's hair. Andrew can't quite stifle a laugh at that, imagining it. "Has to be an alternate universe," he decides. "If he's still calling himself the Doctor...."

That or he's a very young Andrew, but Andrew doesn't remember ever turning into a pony. It seems like the sort of thing that would stick in one's mind. He peers ahead, not sure where Daine is taking him but eager to see his hairy counterpart.