After I watched “The Night of the Doctor” I wondered what would have happened if Cass didn’t hate Time Lords so much and decided to go with the Doctor. He could have had a new companion, she could have seen the universe, and they both could have had a nice time drinking some tea.
I’m not sure what Cass’ uniform really looks like - I watched the short many times. but her outfit wasn’t terribly clear, so I had to guess at it.
Sorry for the bad quality photo, and boy could my drawing be better (5 years in Art School, folks), but I hope you guys enjoy it. :)