I suspect they realised that wall monster masks needed these airholes after Guy Standeven kept sucking his into his face during the first episode.

I've just watched that one... and nothing makes it more obvious that it was a face mask than this. Other than that GS's eyes were just about visible in the eye holes...

The banter between Olgarth, Granitas and Treguard seems a lot more involved in series 1 than series 2. Maybe they'd run out of things the two monsters could say about each other by then?

A couple of times with Igneous, look very carefully and you can see a small breathing-hole in the mask where Edmund Dehn's nose is.

That doesn't tally with what Edmund Dehn has said about Igneous' mask:

'There was the process of taking a cast of my face in plaster of Paris for the Wall Monster's mask. Very alarming! Your whole face covered completely for an hour or more except for 2 small breathing holes - 1 for each nostril!!! The masks were odd as well. They had eye & mouth holes, but no nose holes - different breathing patterns!'

• http://knightmare.com/fanstuff/interviews/eddehn.htm

I'm sure there were scenes in series 2 where the troll was followed by Olgarth or Granitas... and they'd not have been able to keep the kids waiting in the grren room for hours while Guy Standeven had a whole new mask made.

In fact, I think that the Troll only appeared in Level Ones alongside Igneous. This is certainly true of Quests 6 (Akash) and 12 (Steven).

As far as I can see, the only difference between Olgarth and Granitas is Olgarth has a much larger crack in his nose. One day I'll get screenshots of the two side by side... even Treguard was confused once.

"I am Granitas of legend. MY NAME IS NOT AMUSING!"

Oh, yes it is, mate. Even watching that first time round as a nine-year-old that name raised a smirk or two.

Incidentally, would I be right in thinking that the original three wall monsters were something along the lines of Spitting Image puppets - i.e. that's someone's hand in a rubber mask, as opposed to a full face covering? Can't think of any other way they'd have done that... especially given that the two actors both appeared in full face shots in other parts of the quest...

How did the wall monasters end up in the walls in the first place?

The same way that the door monsters wound up in doors - an inanimate object was spell-bound.

As well as threatening to eat dungeoneres they can also help them so I'd say they were neutral.

What about the weeping doors though, as they served a pretty similar purpose. They personally annoyed me

The first strp is the archer....the arrrccchhherrr