This whole bit is made all the funnier by knowing that all of the guards were just random extras who weren’t told what was going to happen only that they weren’t allowed laugh at any cost as they wouldn’t be payed if they did.
At uni I took a screenwriting course from THIS VERY GUARD EXTRA (who went on to contribute to some of the Python stuff), who confirms this and also that Michael Palin would use different ridiculous names in every take, so they couldn’t even prepare themselves for hearing it.
These people are legendary. Heroes of our age.
(He has a wife, you knooooow?)