The Rovie was originally a normal rovie which lived around the Citadel. He had an ordinary life, avoiding the Time Lords and their cleaning machines. When the Doctor came to Gallifrey on a mission, the Rovie hid in his TARDIS. There he lived for many years, with the TARDIS protecting and feeding him. When a remote operation module was installed by Shayde, there was a leak from a temporal relay, exposing the Rovie to the Time Vortex. Instead of being aged to death, the TARDIS tried to protect him, causing him to evolve thousands of years in minutes. He was increased ten times in size, while his brain was increased a thousand times in size. He was able to tap into the TARDIS' memory banks and learn from it. Despite this, he was unable to develop any social skills and was insane.