Malfoy’s mum Narcissa ruined the Doctor’s romantic plans for Amy and Rory in 2010’s The Vampires of Venice. She underwent a dramatic transformation to play Saturnynian queen Rosanna Calvierri, leader of a race of aquatic aliens with vampire-like tendencies.
Speaking of the Malfoys, their former House Elf Dobby – who helped Harry out on many an occasion – was voiced by Toby Jones. That same Toby popped up in Amy’s Choice as The Dream Lord, a representation of the Doctor’s inner darkness who caused quite a bit of trouble.
Sir Michael Gambon
Even dear old Albus Dumbledore has had dealings with The Doctor. Dumbledore 2.0 Sir Michael Gambon took on the Scrooge-like roles of Kazran and Elliot Sardick in 2010 Christmas Special A Christmas Carol.