Ascaris

Ascaris was a mute assassin in Rome. He was hired by a centurion to assassinate Maximus Pettulian, which he succeeded in doing. When the Doctor claimed that he was Maximus, the centurion believed that Ascaris had failed, but gave him another chance. When he tried to kill the Doctor, the Time Lord fought back, and when Vicki joined the melee, Ascaris fled out the window. A previous failure had caused the centurion to cut out his tongue resulting in his muteness. (DW: The Romans)