Stevens (The Green Death)

Stevens was a UNIT soldier serving under Brigadier Lethbridge-Stewart.

Biography
Stevens was part of the convoy sent to Llanfairfach to destroy the giant maggots. (TV: The Green Death)

Behind the scenes
Leslie Bates also played UNIT soldiers in The Three Doctors and Invasion of the Dinosaurs. It is unclear whether these soldiers are meant to be the same character.