During the episode Nightmare in Silver, the Cyber-planner (the leader of the Cybermen, but in essence the collective conciousness of the Cybermen) took over the Eleventh Doctor's body, causing him to 'flashback - in a sense - to previous incarnations, with an exclamation of "Fantastic!" similar to the Ninth Doctor, as well as "Allons-y!", famously spouted by the his predecessor. He also showcased similar characteristics to the Third and Fourth Doctors, too. This wasn't the first time the Eleventh Doctor experienced a blast from the past. His Ganger in the Series 6 episodes The Rebel Flesh and The Almost People reverted to previous regenerations whilst trying to make sense of the complex DNA left behind from those previous regenerations. In this instance, however, voice work from David Tennant and Tom Baker was used to make it sound as if the Eleventh Doctor Ganger was actually reverting, saying what they would say, while sounding like them as well. The Cyber-planner one, though... that was all Matt Smith. And what a splendid job he did!