Many references indeed, but nevertheless this is the first time that I see the full game description with stats.
Where does it come from, exactly (i.e. what is the "original source" mentioned)?

Never had the pleasure to hold it in my hands... thanks for reporting this bit!

PS I expected the Balrogs to be more powerful than 10 HD...

Well, in '74 power bloat hadn't hit yet so 10HD was probably up there with the big guys. Not in the same league as purple worms, but the same as mid-range giants or dragons.

I always did wonder why purple worms were so formidable. I assume Dune had something to do with it. I remember reading something about the topic on the OD&D Discussion boards, I think.

I believe there was a distinct point between Chainmail and OD&D when the dragon also known as a purple or mottled worm ceased being draconic and became nematode. In fact they predate Chainmail:

http://odd74.proboards.com/thread/8122/ ... nmail-1969

But by Monsters & Treasure they were big worms, and didn't the mottled version resurface in similarly slimy form as the mottled worm in Blackmoor at some point?

Sorry, getting off the balrog topic a bit now! But it seems interesting to me that the purple worm became so much more powerful than anything else, at least in terms of hit dice. I stick by my Dune theory!

That is a great link Vile, thanks!

The Dune Series is not a bad theory. I have previously argued that Dave could also have been inspired by Frank Herbert. Ofcourse there is also the obscure reference to Were-wûrms in the Hobbit, which Tolkien based on the Mongolian Death Worm, but I am not sure Gary would have caught that one.

-Havard