There’s a billion universes out there, I think you’ve gotten ours confused with something else. I can assure you my companions aren’t ponies (thought maybe having hooves would make River stop shooting at my hats).

(Mod PS: to the anon who seems to have decided to try to turn everyone into ponies; IF I’m introducing pony-companions (I mean there’s the pony-doc hiding back there…) I’d like to design them myself, and not use other’s designs or background-ponies. I already have a couple of pony-designs, specifically for River, Rose, Jack Harkness and the Ponds posted on my DA.)