Any headcannons about Terror characters that aren't more major characters story-wise in the show? (Like with only a few lines total)
Terror Headcannons for those that are very minor characters...!
Well. Some of which you... "may already know of"... But for the sake of publicity for some of these... "headcannons".
David Young was not very clever with anything. Mind full of rocks. Unless the subject was sailing, maps, or work aboard a ship, this wee lad was pitifully as knowledgeable and experiences as much as he had body weight.
Charles Frederick Des Voeux was polydactyl on one hand but hid it well. He also was left handed though this did nothing for him for he had little to no choice but to write with his right hand due to the stigma against lefthandedness.
Dear Charles was also as sassy and petty as everyone thinks of him from the series as a whole. He is petty, sassy and full of quipping remarks but straightens up very quickly when officers are around, especially ones that have stricter standards like Hodgson.
Thomas and John Hartnell are farmers by trade and family.
George Chambers was picky about food. Not as fond of chocolate as others. Did not really smoke.
George Chambers could drink and drink and it never seemed to impact the young lad.
Chambers also was literate. Which was unusual for the time. He wasn't perfectly literate. But could read, certainly, even if spelling and writing was a much bigger challenge.
John Diggle is the father of nine daughters. No sons and is in fact a very good father and makes his wife very very happy.
How did I do? Were they what you anticipated?