Kevin ( When Worlds Collide ) Kevin was a robot ic copy of a Tyrannosaurus rex who was briefly a companion of the Eleventh Doctor , along with Amy Pond and Rory Williams . Kevin found pretending to be a T - Rex unsettling , so he asked to travel with the Doctor so he could find a better place for himself . Profile . First adventure with the Doctor . Kevin was created as an animatronic amusement for the prehistoric planet setting of a vast resort complex . Possessed of an individual personality , he considered himself more of an actor than a simple automaton and was often concerned with attaining the proper " motivation " to portray his role effectively . When an invading Sontaran fleet caused a temporal rift to form in the complex , Kevin ' s T - Rex programming overcame him . He began attacking everything and everyone in sight , including the Doctor . His personality was eventually restored and he helped the Doctor restore order to the complex , allowing Rory to ride him as a mount to defeat the Sontarans . Disturbed by the experience of momentarily thinking like a real T - Rex , Kevin asked the Doctor if he could travel with him in hopes of finding a better role in life . The Doctor agreed and somehow got Kevin into the TARDIS . ( COMIC : " When Worlds Collide " ) Life as a companion . Kevin ' s size and appearance occasionally caused difficulty in his travels with the Doctor . Unlike the Doctor ' s humanoid companions , Kevin could not blend in easily with many of the societies visited by the TARDIS crew . In his first week aboard the TARDIS , his size hindered a quick escape from Sitting Bull ' s warriors . He later tried and failed to impersonate a detective in 20th century Los Angeles . Kevin ' s tiny arms also caused problems , making it impossible for him to assist the Doctor in piloting the TARDIS . On the positive side , he proved himself adept at scaring away hostile aliens , although Amy admitted that she missed the usual " running away lots " tactic normally employed by the TARDIS crew . Kevin almost caused a panic in Japan when the locals mistook him for a kaiju ( a colossal monster in the vein of the famous " Godzilla " ) and thought he was going to destroy Tokyo . The forlorn robot eventually confessed his troubles to Rory , saying he felt he would never become something better as long as other people judged him by his appearance . Rory consoled him by admitting his own troubles in adjusting to TARDIS life . He reassured Kevin that one day he would find his purpose . When the TARDIS visited Nebula Base , Kevin elected to remain inside the TARDIS , but came to the rescue when his friends were threatened by possessed cult ists . A mind - controlling space squid appeared outside the station and took over the minds of most of the inhabitants , but Kevin and the Doctor were both immune to its powers . After rescuing Amy and Rory from the cultists , the Doctor fashioned a battle suit for Kevin and gave the robotic T - Rex a concoction designed to knock out the cephalopod . Kevin engaged the squid in combat . Making good use of the extended mechanical arms on his battle suit , he defeated the squid and freed the population of the station . Kevin decided to remain on the station as its new chief of security . ( COMIC : " Space Squid " ) Personality . Kevin was generally mild - mannered and polite . He did not enjoy portraying a T - Rex , describing the experience as wanting to kill people but not knowing why and not being able to stop himself . The robot T - Rex was also a capable fighter despite his friendly disposition . He allowed Rory to use him as a mount in combat and carried the Doctor to safety when they were being pursued by the cultists . ( COMIC : " Space Squid " )