Continuity mistake: When George (dressed as Blackadder) is in the cellar and about to go upstairs, he has one cup on his tray, however when he arrives upstairs there are two cups on the tray.
Continuity mistake: When the Shadow shoots at Baldrick to get rid of him, she is aiming over his head but the shot lands at his feet.
Answer: His first name is "Sod Off". Blackadder asks him in series 3 where this came from, and he replies "Well, when I was a kid, living in the gutter, I'd go up to the other kids and say 'Hello, I'm Baldrick'. And they'd say, 'Yes, we know. Sod off, Baldrick.'"
Shay