1. Mark Gatiss (Professor Lazarus/Gantok/Danny Boy/Tycho Nestoris)
Speaking of An Adventure in Time and Space, its writer Mark Gatiss has also appeared in both shows. While he's better known for writing for Doctor Who and has even been tipped as a candidate to take over when his close friend and current showrunner Steven Moffat steps down, he has played three roles in the new series. He voiced the spitfire pilot Danny Boy in Series 5 episode Victory of the Daleks (which he wrote), reprising the role in Series 6's A Good Man Goes to War. He also played Gantok in the Series 7 finale under heavy make-up and the false name Rondo Haxton. However, his biggest role in Doctor Who was the Series 3 villain Professor Lazarus, a scientist who manages to reverse the process of ageing... at the cost of turning himself into a huge life force-sucking monster. Full of his own importance, Lazarus was stopped by the Tenth Doctor who used a church tower and his trusty sonic screwdriver to amplify the sound waves from the church organ to force Lazarus to fall from said church tower to his death. Gatiss hasn't appeared much in Game of Thrones, though, in which he played Tycho Nestoris, an agent of the Iron Bank of Braavos. He appeared across the table from Stannis Baratheon and Davos Seaworth as they requested a loan to pay for an army. Intially sceptical, Nestoris was won over by Davos. While fans haven't seen much of him so far, that's likely to change as Gatiss will be back in Season 5. What did you think of our list? Are there any Docotr Who actors who have been in Game of Thrones, or vice versa, that should've been included? Let us know in the comments section below.
