Handles was a the head of the shell of a Cyberman. He help the Eleventh Doctor towards the end of his incarnation.
Handles was a Cyberman, but somehow the biological components were taken out leaving the technological parts. The Doctor found him at The Maldovarium market. He took it to his TARDIS and repaired him. He named him, "Handles".
Handles helped the Doctor identify a unknown planet, Trenzalore. He said Gallifrey, but the Doctor knew the planet was not Gallifrey. However, there was a crack in time on Trenzalore. The crack was between Trenzalore and Gallifrey. This is what Handles was talking about.
The Doctor also told Handles to remind him to wire the exterior phone back into the interior phone.
Later, the Doctor needed to stay at a town called, "Christmas". During his first 300 years there, Handles was his constant companion. Clara Oswald, the Doctor's companion of the time, was sent back into The TARDIS to her home. She did not want to leave the Doctor, so she went back. On the day that Clara returned, Handles died. His last words were the reminder to the Doctor to rewire the phones.