This was a very random idea I had. It was originally going to be a random guy and girl, but it became Doctor Whooves (technically Tenth Doctor) and Derpy Hooves instead.
I really loved the sketch so I decided to try coloring it. I have a SAI trial version right now, so I decided to put it to good use. Derpy Hooves and the Tenth Doctor belong to their respective owners.
Redrawn on SAI and colored using SAI and GIMP.
Original Sketch here: [link]