Original vectors borrowed from [link]
for Discord Whooves and [link]
ATG Drawing. Chaotic pony. When I read it, I wanted to do a discorded pony, and eventually I settled on Discord Whooves. However, I realized my style wouldn't be able to show it well, so I decided to shade Dr. Whooves and leave Derpy in the usual style. I like the way it turned out.
Drawing prior to shading, if you're curious [link]