Sergeant Who was, within a nightmare Dez Skinn had in 1979, a fictional character created by Colonel Lionel Bluster-Outrage to star in the pre-schooler comic book Sergeant Who's Jelly Baby Adventures. Judging by the cover of the first and only issue ever created, Sergeant Who was a smiling man who experienced many wholesome adventures in the company of life-sized, sentient jelly babies.
Sergeant Who was actually born of the Colonel's misunderstanding of what Skinn tried to tell him about the Doctor (specifically resembling the Fourth Doctor): initially turned from a "medic" into a sergeant by the Colonel on the mistaken belief that Doctor Who was to be a war comic, he was made into a sanitised pre-school figure when Skinn mentioned jelly babies. (NOTVALID: The Origin of Doctor Who Magazine)