Harvey Parson

H. Parson was the headmaster at Coal Hill School in 1963, and by extension Ian and Barbara's boss. (DW: An Unearthly Child) At an unknown point the Imperial Daleks took control of him and used him as an undercover agent, implanting a thin device behind his ear. He was presumably killed when the Imperial Daleks exterminated him (likely via his implant) so that Mike Smith could not get information out of him. (DW: Remembrance of the Daleks)