Fans believe that all four of these are the same pony, and that his name is Doctor Whooves. That is correct.
my little poney x Doctor and River Equestria Daily: Drawfriend Stuff #349 - Derped the Title Edition
YEESSS hahaha I've actually seen that episode! Every time Doctor Whooves popped up somewhere I fangirlled quite a bit.
Doctor Whooves Explains Time by Owlstar7.deviantart.com on @DeviantArt
Jack Harkness, nice to meet you by *MadHotaru on deviantART i love this so much xD
My Little Pony Friendship Is Magic - Front Row Crew Forum
Doctor Whooves Found A Terrifying Nemesis
Note to self: use this joke more often THAT FACE; Doctor Whooves and Ditzy Doo Derpy Hooves
my little pony, friendship is magic made a Doctor Who pony
So cute! I want that doctor whooves ditzy doo derpy hooves