Derrick Sherwin
Derrick G. Sherwin (born 16 April 1936 in High Wycombe, England, died 17 October 2018[1]) was script editor of Doctor Who from The Web of Fear to The Mind Robber. Immediately after his departure as script editor, he wrote The Invasion and briefly returned as script editor for The Space Pirates. He was the producer from The War Games to Spearhead from Space, overseeing the transition from Patrick Troughton's Second Doctor to Jon Pertwee's Third Doctor, the production's conversion from monochrome to colour, and the retooling of the series to one of Earth-bound, present-day adventures. (DOC: The UNIT Family) However, Sherwin is the shortest-serving producer of the classic era of Doctor Who, having produced only two serials consecutively.
Sherwin, as well as being script editor and producer, was also an actor, with several roles on television in the 1950s and 1960s. He made a cameo appearance in The Invasion where he stepped in as a non-speaking and uncredited UNIT attendant. (DWM 533) He also had an uncredited role in Spearhead from Space as a UNIT commissionaire. (DOC: Down to Earth)
He notably added the sonic screwdriver into Victor Pemberton's script for Fury from the Deep. So, from that perspective, Sherwin can be seen as it's creator.
His wife, Jane Sherwin, whom he had met as an actor, played Lady Jennifer Buckingham in his first story as producer, The War Games.