Tom Osgood

Sgt. Tom Osgood was a UNIT technical officer who served under Brigadier Lethbridge-Stewart.

Biography
Osgood joined UNIT shortly before the Third Doctor's arrival, as a corporal. He was the most technically proficient UNIT soldier. (PROSE: The Eye of the Giant)

After he was promoted to Sergeant, he was called in to assist in the rescue of the Doctor, Jo Grant, Sergeant Benton and Captain Yates. With the Doctor's help, he devised a way to get past the heat barrier surrounding Devil's End. (TV: The Dæmons)

Soon after this, Osgood became engaged to a woman named Becky, whom he met at a folk festival (possibly the Devil's End festival). (PROSE: Dancing the Code)

In his fifties, Osgood worked as a scientific advisor for UNIT. (PROSE: The Shadow in the Glass)

Behind the scenes

 * Osgood's first name was not given on-screen, only in PROSE: The Eye of the Giant.