Uriel (Sunday Afternoon, AD 848,988)

Uriel was, according to the Seventh Doctor, a Raagr'an from somewhere near Betelgeuse. He pretended to be a Time Lord that had been stranded in Prague in 1380. When the Doctor rescued him, however, he commandeered the TARDIS, leading to a series of events that created a paradox. (PROSE: Sunday Afternoon, AD 848,988)