Handles

 was the nickname given to a Cyberman head repaired by the Eleventh Doctor after he got it in the Maldovarium Market. It went on many adventures with him as he searched the mysterious Trenzalore. When the Doctor ended up staying there for many years, Handles was his only companion for three hundred years, before it shut down, at the same time finally fulfilling an order he'd given it three hundred years before. Handles death reduced the Doctor to tears.