Catherine Tate show + Doctor Who + HP = Awesome (also, if Fred and George played the doctor, can you imagine? Doctor split during regeneration.Moffat could just go crazy)(AND HE WOULD FINALLY BE GINGER!
Holy crap I didn't know the guy who played Barty Crouch Jr. in Harry Potter is actually the same actor who is the one and only Doctor on Doctor Who holy crap that's awesome. Well that case Harry Potter would be screwed.
:) They could put Slytherin at the bottom and have a pic of the Master. Even though I think any doctor would be good in any house. He's cunning(Slytherin), smart(Ravenclaw), kind(Hufflepuff), and brave(Gryffindor)