Remember when I mentioned that My Little Pony: Friendship is Magic had some geeky tie-ins? Well, there's a male pony who has appeared in the background repeatedly and had one speaking part in the series who happens to have an hourglass as his cutie mark (that's the symbol on every pony's flank). He also has spiky hair that's reminiscent of a certain Doctor. Thusly, fans have dubbed him Doctor Whooves. Yes, David Tennant can be a pony. Why not?
Like any good name, it stuck. The crew started calling the Earth pony by that name and Hasbro even featured the character in its 2011 promotional poster for Comic-Con. And because fans are fans and we tend to be hardcore (you've probably noticed), people go gaga over the character. Doctor Who fans check out the animated series just to spot the Time Lord in his equestrian form. As you can imagine, there is a veritable ton of fan art of this pony and even a comic strip.
Even cooler than that? Ocarinaplaya has made two episodes of an animated cartoon called Doctor Whooves and Assistant starring the time traveling pony and a companion. It's adorable and fun and worth watching (even if you just like Doctor Who and not ponies or vice versa):
(source: The Mary Sue)